Author Topic: Broken IC on old Pentium 2 motherboard  (Read 13121 times)

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Offline spilihpsTopic starter

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Broken IC on old Pentium 2 motherboard
« on: October 16, 2019, 07:06:48 pm »
Hello!

So i have had an old P2 pc to play around with some old software. And tonight when i went on and started it up, i could hear a loud pop from inside the PC.
First i thought it was the PSU, but it was still running and all voltages checked out fine. Took it apart to investigate the motherboard, and found this IC that had a chunk blown away.
Please see the attached image.

There is not much info that i could find with a quick google search. It seems to be a over-current protection IC.
Got any ideas why this happened? Could it be just the IC itself or some other problem?
I did replace all electrolytic capacitors on the board when i took it out of storage. Been running fine for about 2 months now..

Possible replacement chips?
 

Offline fzabkar

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Re: Broken IC on old Pentium 2 motherboard
« Reply #1 on: October 16, 2019, 07:22:52 pm »
www.electroscheme.ru/datasheet/AIC/AIC1569.PDF

Check the +12V supply from your PSU, and the two nearby MOSFETs.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #2 on: October 16, 2019, 08:08:14 pm »
Thank you very much for your input.

The two MOSFETs are not a dead short when i measure them in circuit at least. Have to pull them to be sure they are okey though.

The +12v rail measures fine, however i cannot be sure if it had a "spike" of some sort?

It seems that the AIC1569 is not available for purchase anywhere, however the one that is referred as compatible "HIP6004" is on ebay.
Seems like its a drop in replacement?
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #3 on: October 16, 2019, 08:59:12 pm »
this chip blowing up can mean 5V went into CPU
Id triple check those power transistors, and the diode, and measure if CPU is not a dead short now
HIP6004 will be fine
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #4 on: October 16, 2019, 09:27:21 pm »
this chip blowing up can mean 5V went into CPU
Id triple check those power transistors, and the diode, and measure if CPU is not a dead short now
HIP6004 will be fine

Thanks for your help!

well thats no good. especially if its designed to protect it  :-//

I can remove the transistors tomorrow to check their functionality, however, as they sit right now in circuit, they are not shorted atleast.
Will also check the diode. Not really sure were to check if the CPU is dead short though?

The question is if these chips fail by themself or if there were something else that made it pop?
 

Offline fzabkar

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Re: Broken IC on old Pentium 2 motherboard
« Reply #5 on: October 16, 2019, 10:01:11 pm »
The junction of the two MOSFETs connects to a coil, and this coil would connect to the CPU's core. So measuring the resistance between the coil and ground should tell you if the core is shorted.

See the application circuit on page 2 of the datasheet. Vout is Vcore.
 

Offline amyk

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Re: Broken IC on old Pentium 2 motherboard
« Reply #6 on: October 17, 2019, 01:17:55 am »
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #7 on: October 17, 2019, 02:56:44 am »
especially if its designed to protect it

its not, primary function is variable voltage buck converter controller/driver, secondary is monitoring
Quote
PGOOD and OVP comparator circuits use this signal to report output voltage status
there are no protections without outside circuity like
Quote
Built-in over-voltage protection triggers an external SCR to crowbar the input supply.

The question is if these chips fail by themself or if there were something else that made it pop?

Sometimes things just die, but external cause is more likely. Either big spike on 12V rail, or maybe one of the mosfet gates blown/leaking back to the driver (pins 14 and 17).

I was active in pc parts around 1998-2006, dead motherboards were very rare. We (national Euro Asus distributor) had literally single bad Asus motherboard in over a year of bulk sales (P2L97), we did get tens of pcchips garbage back every month, but almost all "just" crashed/had bad drivers/compatibility/were outright scams with fake features like non existent 3d acceleration/agp.
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Online NiHaoMike

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Re: Broken IC on old Pentium 2 motherboard
« Reply #8 on: October 17, 2019, 03:13:53 am »
Unless you need ISA slots, wouldn't it be easier to just replace the machine with a somewhat newer old machine? You could even underclock/undervolt to dramatically reduce the heat output.
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #9 on: October 17, 2019, 07:20:55 am »
especially if its designed to protect it

its not, primary function is variable voltage buck converter controller/driver, secondary is monitoring
Quote
PGOOD and OVP comparator circuits use this signal to report output voltage status
there are no protections without outside circuity like
Quote
Built-in over-voltage protection triggers an external SCR to crowbar the input supply.

The question is if these chips fail by themself or if there were something else that made it pop?

Sometimes things just die, but external cause is more likely. Either big spike on 12V rail, or maybe one of the mosfet gates blown/leaking back to the driver (pins 14 and 17).

I was active in pc parts around 1998-2006, dead motherboards were very rare. We (national Euro Asus distributor) had literally single bad Asus motherboard in over a year of bulk sales (P2L97), we did get tens of pcchips garbage back every month, but almost all "just" crashed/had bad drivers/compatibility/were outright scams with fake features like non existent 3d acceleration/agp.

Thats cool, i thought that were the high times for the capacitors that leaked? Remember several boards doing that at those times.

Thank you for all your help!

I did a quick check this morning and Vout is not shorted to ground. Will pull the diode and the transistors tonight to properly test them out. If they check out i will drop in a replacement and see what happens? 
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #10 on: October 17, 2019, 05:59:26 pm »
Thats cool, i thought that were the high times for the capacitors that leaked? Remember several boards doing that at those times.

That was mainly Abit, MSI, Gigabyte, ECS and fleet brands like HP and DELL. Afaik Asus switched to Taiwanese caps after 2006 when it came out everyone else was screwed and capacitor vendors started claiming fixes.

I did a quick check this morning and Vout is not shorted to ground. Will pull the diode and the transistors tonight to properly test them out. If they check out i will drop in a replacement and see what happens?

means diode is also fine
how is AIC1569 powered on your board? is it single 12V or dual supply setup? might be prudent cutting 12V and powering it from external limited current supply when testing.
« Last Edit: October 17, 2019, 06:01:34 pm by Rasz »
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #11 on: October 18, 2019, 08:40:52 pm »
Quote
means diode is also fine
how is AIC1569 powered on your board? is it single 12V or dual supply setup? might be prudent cutting 12V and powering it from external limited current supply when testing.

Yes! i see, thats good! I leave the diode in then.
The thing left to pull and test out of circuit is the transistors?

About the supply for the chip, from what i can gather, the VCC is directly connected to +12v of the PSU connector on the board, if that is what you meant?
As you can tell, iam a bit out of my league here  :-DD



I have ordered replacement chips from china, so it will be a couple of weeks.
 
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #12 on: October 20, 2019, 04:06:09 pm »
A small update on this.

So i pulled both of the transistors out. And a simple switch test with my multimeter shows they are operating normal.
May replace them just in case anyway?

 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #13 on: November 21, 2019, 05:03:29 pm »
So, finally today i received the control ICs. So i soldered that one in place, also re-used the old FETs, since they at least passed the switch test.
But no go.

Nothing bad happened though, (as in exploding), the cpu fan turns on, and nothing more.  I was giving up, but just for a quickie i hooked my scope up, and i could see signals on all pins on the second FET, (the one furthest from the cpu), and signals on Gate and drain on the first one, but a total flat-line on the source.
What could this indicate? Now, it was just a super quick check, so didnt take note on the levels or frequency, but if that might help i can hook it up once more.
 

Offline magic

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Re: Broken IC on old Pentium 2 motherboard
« Reply #14 on: November 21, 2019, 05:55:44 pm »
It could mean it's synchronous rectification and the source is hard-wired to ground ;)

Better check what's the voltage on the CPU side of the coil and if there is significant ripple.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #15 on: November 21, 2019, 11:13:25 pm »
It could mean it's synchronous rectification and the source is hard-wired to ground ;)

Better check what's the voltage on the CPU side of the coil and if there is significant ripple.

Yeah, haha, as stated before, im a bit way over my head here!
By the coil, do you refer to Vout after L2 or 5V after L1 as in the typical application circuit of the datasheet?

Will hook it up to a more "permanent" test bench, the one before was dodgy to say the least.

 

Offline magic

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Re: Broken IC on old Pentium 2 motherboard
« Reply #16 on: November 22, 2019, 08:09:54 am »
By the coil, do you refer to Vout after L2 or 5V after L1
Whatever is the power output to the CPU; Vout sounds like it might be it, 5V not so much.

typical application circuit of the datasheet?
Wait, if you have the datasheet you should know how the FETs are connected :P
I bet one is meant to go to ground and there is nothing wrong with it.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #17 on: November 28, 2019, 06:45:06 pm »
Yes your right!
So i took some measurements on the Vout, and i get a mean value of 1.263v.

I attach a screenshot from the scope
The bet is that the cpu also died i guess?
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #18 on: November 28, 2019, 06:49:18 pm »
Unless you need ISA slots, wouldn't it be easier to just replace the machine with a somewhat newer old machine? You could even underclock/undervolt to dramatically reduce the heat output.

That's completely missing the point of playing with retro hardware. If one just wants to run certain software, virtually any old PC can be emulated but that's nowhere near the same.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #19 on: November 28, 2019, 06:53:15 pm »
Unless you need ISA slots, wouldn't it be easier to just replace the machine with a somewhat newer old machine? You could even underclock/undervolt to dramatically reduce the heat output.

That's completely missing the point of playing with retro hardware. If one just wants to run certain software, virtually any old PC can be emulated but that's nowhere near the same.

Yeah exactly my point! Thanks for understanding. Also, i am the original owner of this board, that has to account for some sentimental value, right? ;)
Best of all, trying to fix it, one might learn something.
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #20 on: November 28, 2019, 08:36:16 pm »
So i took some measurements on the Vout, and i get a mean value of 1.263v.

thats too low. You didnt mention exact model of your processor, Ill wager a guess its something popular like 333, those need 2V
Measure resistance on Vcore rail with CPU in the slot. Check VID[4:0] setup, pinout of SLOT1 is at https://web.archive.org/web/20060622200013/http://developer.intel.com/design/pentiumiii/datashts/24445209.pdf

You could hardwire VID pins without the CPU and recheck generated voltage.
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #21 on: November 28, 2019, 08:42:48 pm »
Oh okey. This is a p2 350mhz. And now I see it is marked with 2.0v on the case itself.

Will try what you suggested, thanks!
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #22 on: November 28, 2019, 09:38:40 pm »
So the resistance is 340ohm with the cpu in the slot.

By "check VID4 setup" do you mean how it is connected on this specific board, or how its signal is when powering the board? Sorry for not catching that.
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #23 on: November 29, 2019, 12:33:35 am »
VID pins in the cpu slot program hip6004 voltage
there is a table in linked pdf explaining how
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #24 on: November 29, 2019, 07:15:04 pm »
VID pins in the cpu slot program hip6004 voltage
there is a table in linked pdf explaining how

Ah i see!

So firstly, i checked VID0..4 when CPU in slot and it gets 10000, this corresponds to 2.0v as stated in the datasheet.
Removed the CPU, and then all gets to 11111.

Did as you said and hardwired them so they get 10000, still the same output voltage.

The strange thing is though, when they are 11111 they get that same voltage also. According to the datasheet i think it should be no output?
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #25 on: November 30, 2019, 04:41:09 am »
This is actually quite interesting, back when I had a PII I didn't really know much about the technical side of the hardware. I remember having to manually set the CPU core voltage of an older system using jumpers on the board though. Never really occurred to me how the later stuff automatically took care of that but it makes perfect sense now.
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #26 on: November 30, 2019, 05:10:41 am »
Im guessing those mosfets arent all that healthy after all, or the diode went bad. Its also possible replacement chip is a dud.
if you have a scope put a probe on pins 14 and 17, if not I would just replace mosfets and diode, maybe even the electrolytic cap behind the coil.

james_s slot1 was pretty sweet for cheapskates, in 1998 a strip of insulation tape on pin B21 (+optionally three VID pins for 0.2V Vcore bump) was all one needed to make $150 Celeron 300A ~equal (sometimes even faster due to 2x faster cache) to fastest Intel offering at the time - $670 Pentium II 450MHz.
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Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #27 on: November 30, 2019, 06:21:13 am »
The one I had right around that time was a PII-300 (not Celeron) which was one of the later ones that would run at 450MHz right out of the box. Didn't even have to mess with the voltage, IIRC it was just a matter of setting the FSB to 100MHz vs 66. I used that machine for years and it was rock solid, later I gave it to my mom and she used it for several more years.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #28 on: November 30, 2019, 11:52:32 am »
This is actually quite interesting, back when I had a PII I didn't really know much about the technical side of the hardware. I remember having to manually set the CPU core voltage of an older system using jumpers on the board though. Never really occurred to me how the later stuff automatically took care of that but it makes perfect sense now.

Yeah, this is something i never payed much attention to either. and i guess when a board failed no matter how, one would just throw it away.

Im guessing those mosfets arent all that healthy after all, or the diode went bad. Its also possible replacement chip is a dud.
if you have a scope put a probe on pins 14 and 17, if not I would just replace mosfets and diode, maybe even the electrolytic cap behind the coil.

james_s slot1 was pretty sweet for cheapskates, in 1998 a strip of insulation tape on pin B21 (+optionally three VID pins for 0.2V Vcore bump) was all one needed to make $150 Celeron 300A ~equal (sometimes even faster due to 2x faster cache) to fastest Intel offering at the time - $670 Pentium II 450MHz.


Yeah, it would be very likely that they are bad in some way. Please see these images from the scope.

Pin 14 and 17 (these signals are present at the mosfets also)
I took snapshots of the drains on the mosfets also,  they seem a bit sketchy?

 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #29 on: November 30, 2019, 07:19:52 pm »
That second one doesn't look right, looks like it's just noise. I don't have a schematic in front of me so I'm not quite sure what should be there but I'd expect something similar to the others.

Are you sure all of the diodes are good?
 

Offline magic

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Re: Broken IC on old Pentium 2 motherboard
« Reply #30 on: November 30, 2019, 07:31:48 pm »
It has to be the high side switch, so its drain is just the 5V rail with bursts of switching noise ;)
Meanwhile the low side switch drain shows 1/3 duty cycle PWM.

The waveforms are plausible, I think, but 1/3 duty cycle is not enough for 2V output from 5V. So either the output voltage sense network is screwed up (check all resistors from Vout to FB/COMP) or perhaps some overcurrent limiting or other protection is kicking in :-//
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #31 on: November 30, 2019, 07:53:47 pm »
Yes it may be something with the sense, since that is also at 1.2v even when i made VID 11111 (that should switch it off i think?)

Will try to trace it out
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #32 on: November 30, 2019, 09:53:06 pm »
Quick update, so just for giggles, i checked the PGOOD pin, and it is at 3.3v. It should be low if it thinks that vsen is out of bounds.. So for some reason it thinks that it is OK?
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #33 on: November 30, 2019, 10:24:22 pm »
That's pgood output from that regulator and not an input from the main PSU? You probably know already but ATX PSUs have a power good output that tells the motherboard when the PSU thinks everything is good to go.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #34 on: November 30, 2019, 10:43:44 pm »
That's pgood output from that regulator and not an input from the main PSU? You probably know already but ATX PSUs have a power good output that tells the motherboard when the PSU thinks everything is good to go.

Hello, no this is an output from the chip itself, from the datasheet:
PGOOD (Pin 12)
PGOOD is an open collector output used to indicate the status
of the converter output voltage. This pin is pulled low when the
converter output is not within 10% of the DACOUT reference
voltage.
 

Offline magic

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Re: Broken IC on old Pentium 2 motherboard
« Reply #35 on: November 30, 2019, 10:50:50 pm »
Looking at the datasheet, it seems that the reference DAC may be outputting wrong voltage. See what's going on at the FB pin.

You said you can pull out the CPU and set the voltage manually? What happens if you set it to something other than 2V?

At any rate, it looks like the chip may be bad.
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #36 on: December 01, 2019, 12:40:19 am »
That second one doesn't look right, looks like it's just noise. I don't have a schematic in front of me so I'm not quite sure what should be there but I'd expect something similar to the others.

second one is +5V supply, and other than lots of ringing (might need caps replaced) looks ~normal for synchronous buck converter.

Yes it may be something with the sense, since that is also at 1.2v even when i made VID 11111 (that should switch it off i think?)

Intel spec might say 11111 is invalid/off, but both original and replacement chips datasheets treat all ones as default 2.0 Volt. You have to set something different to see if anything changes (duty cycle). Pull VID2 to ground and lets see if that 1.263v goes up at all. Measure FB and COMP pins before/after too, as magic says there might be something wrong with compensation circuit - one of small smd resistors/capacitors might of went poof together with the chip.

I would replace electrolytic capacitor after the Vcore output coil just in case.
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #37 on: December 01, 2019, 04:14:07 pm »
That second one doesn't look right, looks like it's just noise. I don't have a schematic in front of me so I'm not quite sure what should be there but I'd expect something similar to the others.

second one is +5V supply, and other than lots of ringing (might need caps replaced) looks ~normal for synchronous buck converter.

Yes it may be something with the sense, since that is also at 1.2v even when i made VID 11111 (that should switch it off i think?)






Intel spec might say 11111 is invalid/off, but both original and replacement chips datasheets treat all ones as default 2.0 Volt. You have to set something different to see if anything changes (duty cycle). Pull VID2 to ground and lets see if that 1.263v goes up at all. Measure FB and COMP pins before/after too, as magic says there might be something wrong with compensation circuit - one of small smd resistors/capacitors might of went poof together with the chip.

I would replace electrolytic capacitor after the Vcore output coil just in case.

Edit: For some reason my text got embedded in the quotes.

It sure did, setting 11011 gets us up to 1.44V


Also, i tried to take some measurements of the resistors / caps that is for the vsen network. However, difficult since i think i need to pull each one to get an accurate reading. No shorts at least.


I include before and after snapshots from the scope, ( I think i managed to not mix them up  :-//  ;D)
« Last Edit: December 01, 2019, 08:03:45 pm by spilihps »
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #38 on: December 01, 2019, 09:00:50 pm »
Those readings + PGOOD make me think its acting like VID4 is internally read low all the time. Pull all VID pins to the ground and lets see if it produces 2.00V.
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #39 on: December 01, 2019, 09:26:40 pm »
Those readings + PGOOD make me think its acting like VID4 is internally read low all the time. Pull all VID pins to the ground and lets see if it produces 2.00V.

No go, 1.266V
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #40 on: December 01, 2019, 09:31:18 pm »
Has this IC been replaced already? It really sounds like something is not right.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #41 on: December 01, 2019, 09:32:55 pm »
You mean that it was a pull? Dont think so, it was in a reel package, and the legs looked fine. However, i did recieve 5 of them, you think its worth a shot to replace it again? Before pulling every resistor on the sense  :-DD
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #42 on: December 02, 2019, 12:48:50 am »
Oh I just meant is this the IC that blew up that you already replaced, sounds like it is. You're sure it's exactly the same as what was there and not a variation with some different parameters? I'm not familiar with this specific family of part but I've worked with other power management ICs that have multiple slightly different part numbers that have various differences. I suppose you could try swapping in another IC, but I would first try every combination of the configuration lines, then check very carefully all of the parts in the feedback loop and if you haven't already, make sure all of the config lines have continuity all the way back to the IC pin and that none are shorted to each other by a solder bridge, etc. Also I would test it while driving a load, probably best not to use the CPU itself, but maybe a power resistor, shouldn't really matter but it's possible that it doesn't like an open circuit.
 

Offline magic

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Re: Broken IC on old Pentium 2 motherboard
« Reply #43 on: December 02, 2019, 08:36:04 am »
I don't think it's the feedback network because power good also indicates that voltage is within regulation and it uses a separate pin to sense the output directly.

Maybe check if the voltage at the input to power good circuit is the same as elsewhere, but at this point I suspect that it is and the chip simply generates wrong reference voltage internally.

Maybe it's a different part, maybe it's fake, maybe you need to replace all capacitors on the chip's supplies, no idea :-//

Also I would test it while driving a load, probably best not to use the CPU itself, but maybe a power resistor, shouldn't really matter but it's possible that it doesn't like an open circuit.
IIRC this was tried already and output voltage was the same with the CPU or without.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #44 on: December 02, 2019, 06:56:53 pm »
Guys, i think i have received the wrong part.
I have recieved HIP6004E instead of HIP6004.
It seems to be variable from 1.050 to 1.825 instead  |O  |O  |O

Im so sorry guys that i took your time with this. Completely my fault. Will try to source the correct part from somewhere.
« Last Edit: December 02, 2019, 07:11:25 pm by spilihps »
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #45 on: December 02, 2019, 07:15:02 pm »
Guys, i think i have received the wrong part.
I have recieved HIP6004E instead of HIP6004.
It seems to be variable from 1.050 to 1.825 instead  |O  |O  |O

 :-DD that explains everything. This is VRM 8.5 specification for FCPGA socket boards (Coppermine/Tualatin) https://www.tomshardware.com/reviews/intel-roadmap-news-10,252-3.html
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Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #46 on: December 02, 2019, 08:22:58 pm »
Well it sounds like you've at least validated that the rest of the parts are ok so all you have to do now is source the correct IC and swap it. That's an even more subtle difference in the part number than I'd have expected, you'll have to check carefully that any vendor actually sends you the exact part you ordered.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #47 on: December 02, 2019, 09:20:21 pm »
Guys, i think i have received the wrong part.
I have recieved HIP6004E instead of HIP6004.
It seems to be variable from 1.050 to 1.825 instead  |O  |O  |O

 :-DD that explains everything. This is VRM 8.5 specification for FCPGA socket boards (Coppermine/Tualatin) https://www.tomshardware.com/reviews/intel-roadmap-news-10,252-3.html

Yeah i cannot believe it! Thanks for the info. And again, thank you for all your input and knowledge about this. Will keep you posted when the HIP6004CB (What i think is the right  :-DD) Found a seller on ebay in china. Probably will have to wait over a month again. Seem to be impossible to get hold of these in Europe?


Well it sounds like you've at least validated that the rest of the parts are ok so all you have to do now is source the correct IC and swap it. That's an even more subtle difference in the part number than I'd have expected, you'll have to check carefully that any vendor actually sends you the exact part you ordered.

Yeah your right, this probably means that with the right part dropped in, everything should work. If there is no other problems somewere else after the other blew up.

Yeah, the partnumbers were not that easy to catch. It seems like i want the one that is HIP6004CB and found a seller on ebay in china.
Also, thank you for all your help and patients with this. Cant belive i wasted everyones time with this silly partnumber missmatch.
 

Offline magic

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Re: Broken IC on old Pentium 2 motherboard
« Reply #48 on: December 02, 2019, 09:38:58 pm »
 :-DD

Do you think that old Pentium would stand a chance at 1.825? ;)
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #49 on: December 02, 2019, 09:54:14 pm »
:-DD

Do you think that old Pentium would stand a chance at 1.825? ;)

Are you suggesting hard wiring it up to 1.825 and see if it works?  ::)
 

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Re: Broken IC on old Pentium 2 motherboard
« Reply #50 on: December 02, 2019, 11:23:31 pm »
Probably won't work unless you can also underclock the CPU with jumpers but what the heck, better than waiting a month :P
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #51 on: December 03, 2019, 12:57:28 am »
Yeah i cannot believe it! Thanks for the info. And again, thank you for all your input and knowledge about this. Will keep you posted when the HIP6004CB (What i think is the right  :-DD) Found a seller on ebay in china.

"1PCS HIP6004BCB HIP6004BCB-T SOP20 SMD Buck and Synchronous-Rectifier PWM
 $3.28 or Best Offer FREE Economy International Shipping" one also looks good

Probably will have to wait over a month again. Seem to be impossible to get hold of these in Europe?

20 year old highly time period specific (relevant for only ~3-4 years) chip, I would look for Slot1/socket370 motherboards with compatible chip at the scrap/local classifieds, or hotwire $3 "100W" chinese DC-DC module
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Offline pcmad

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Re: Broken IC on old Pentium 2 motherboard
« Reply #52 on: December 03, 2019, 01:31:13 am »
i got lot of old  Pentium 2 motherboard if you need parts pm me

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #53 on: December 03, 2019, 01:43:44 am »
Waiting a month doesn't seem so bad if it means getting exactly the correct part you need to fix your board.
 

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Re: Broken IC on old Pentium 2 motherboard
« Reply #54 on: December 03, 2019, 02:42:27 am »
I have run a 733MHz P3 underclocked to 533MHz on 1.25V (normal core voltage about 1.8V) for a pfSense router in order to reduce heat and power consumption, worked flawlessly for years until it was replaced with a newer system. (Quite a few pfSense builders back in the day did similar stuff, although undervolting was not very common.)
Cryptocurrency has taught me to love math and at the same time be baffled by it.

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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #55 on: December 03, 2019, 08:27:14 am »
Yeah i cannot believe it! Thanks for the info. And again, thank you for all your input and knowledge about this. Will keep you posted when the HIP6004CB (What i think is the right  :-DD) Found a seller on ebay in china.

"1PCS HIP6004BCB HIP6004BCB-T SOP20 SMD Buck and Synchronous-Rectifier PWM
 $3.28 or Best Offer FREE Economy International Shipping" one also looks good

Probably will have to wait over a month again. Seem to be impossible to get hold of these in Europe?

20 year old highly time period specific (relevant for only ~3-4 years) chip, I would look for Slot1/socket370 motherboards with compatible chip at the scrap/local classifieds, or hotwire $3 "100W" chinese DC-DC module

Yeah, that will also work. But i ordered "5PCS HIP6004CB Encapsulation:SOP" instead. Do have the exact (atleast in the title) as in the datasheet we used.


Waiting a month doesn't seem so bad if it means getting exactly the correct part you need to fix your board.

Yes you are right! And hopefully it will be the right part this time  :-DD

I have run a 733MHz P3 underclocked to 533MHz on 1.25V (normal core voltage about 1.8V) for a pfSense router in order to reduce heat and power consumption, worked flawlessly for years until it was replaced with a newer system. (Quite a few pfSense builders back in the day did similar stuff, although undervolting was not very common.)

Thats cool, thanks for the input. Although tempting, i will just have to wait :-//


Probably won't work unless you can also underclock the CPU with jumpers but what the heck, better than waiting a month :P


Haha yes!
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #56 on: December 30, 2019, 09:59:48 pm »
Update to this never ending story!

I recieved the IC today, solder it in place. and 2.0V!! Plugged in the CPU, No go..
No VGA..

With the CPU in the slot, i get 1.98V..

CPU toast, or maybe something else?
 

Offline pcmad

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Re: Broken IC on old Pentium 2 motherboard
« Reply #57 on: December 31, 2019, 12:29:05 am »
how are the caps
i had to replace capn on i few slot 1 recently

quick way to cheak turn in on leve it for 10 mins and feel which caps and warm / hot

also

try using IPA to clean the cpu slot thatcan also fix a non runner

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #58 on: December 31, 2019, 03:02:54 am »
You will need another CPU as a sanity check, its highly probably current one received 12V. better yet another working slot1 system to check all components (ram, vga).

I assume you did plug PC speaker? :) Post card is your friend, they are $4 Free International Shipping nowadays.
You can use keyboard in lieu of a post card as a makeshift indicator for running CPU:
-connect only motherboard/ram/cpu/supply and keyboard
-power on, watch for keyboard leds blinking - keyboard controller initialization is very early in the boot sequence

also try with no ram and listen for pcspeaker, beeping for no ram is even earlier in BIOS boot sequence.

Alternatively you can make your very own post card with 74LS138, 74LS374 or 74LS688, 74LS244 and 8 leds or $4 CY7C68013A ebay board.

..or just stick oscilloscope/logic probe on isa address/data bus (or BIOS chip legs) and watch for any activity.

You might find this thread helpful to get an idea of how to approach debugging: https://www.eevblog.com/forum/repair/how-to-troubleshoot-your-defective-386486-motherboard-with-an-oscilloscope/

Its possible CPU was killed by 12V and while dying passed it to the chipset. Are you up for BGA replacement lessons? might be fun! :)
« Last Edit: December 31, 2019, 03:16:43 am by Rasz »
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Offline magic

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Re: Broken IC on old Pentium 2 motherboard
« Reply #59 on: December 31, 2019, 08:50:03 am »
Beware that some keyboards blink by themselves when power is applied.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #60 on: December 31, 2019, 02:53:24 pm »
You will need another CPU as a sanity check, its highly probably current one received 12V. better yet another working slot1 system to check all components (ram, vga).

I assume you did plug PC speaker? :) Post card is your friend, they are $4 Free International Shipping nowadays.
You can use keyboard in lieu of a post card as a makeshift indicator for running CPU:
-connect only motherboard/ram/cpu/supply and keyboard
-power on, watch for keyboard leds blinking - keyboard controller initialization is very early in the boot sequence

also try with no ram and listen for pcspeaker, beeping for no ram is even earlier in BIOS boot sequence.

Alternatively you can make your very own post card with 74LS138, 74LS374 or 74LS688, 74LS244 and 8 leds or $4 CY7C68013A ebay board.

..or just stick oscilloscope/logic probe on isa address/data bus (or BIOS chip legs) and watch for any activity.

You might find this thread helpful to get an idea of how to approach debugging: https://www.eevblog.com/forum/repair/how-to-troubleshoot-your-defective-386486-motherboard-with-an-oscilloscope/

Its possible CPU was killed by 12V and while dying passed it to the chipset. Are you up for BGA replacement lessons? might be fun! :)


The speaker is not to be trusted in this, i cannot remember if i ever heard it beep. And my other chassis are at storage right now  :palm:
And i know i have a second CPU somewere, turned upside down on the house looking for it without any luck!

However, i hooked the scope up to the ISA slot, and probed around. There is "traffic" on both adress and data with the CPU in the slot, and nothing without the CPU.

A Post-card seems to a very good idea in this case. Any schematics for this? i do have the logic chips you refer to, but the schematic i found were for a more advanced one with LED-display & EPROM and such.

I do however have access to a logic analyzer.
 

Offline magic

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Re: Broken IC on old Pentium 2 motherboard
« Reply #61 on: December 31, 2019, 08:21:08 pm »
Where I live I could buy one cheaply on a local auction site and have it here by the end of the week.

In fact, I have one, exactly form such source, procured in circumstances similar to yours.
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #62 on: January 01, 2020, 07:22:31 pm »
Just buy a POST card, they are so ridiculously cheap now, it's not worth your time to build one even if you have the ICs.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #63 on: January 01, 2020, 07:27:08 pm »
Hehe yeah, well. Only available in china = 1 month delivery time again. So in total i have waited for parts from china for 3 months for this board  ;D ;D ;D
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #64 on: January 01, 2020, 07:29:40 pm »
Just start a few more projects, then you'll have something to work on while you wait for parts to show up for the other stuff.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #65 on: January 02, 2020, 06:17:31 pm »
So i managed to dig out a speaker finally!

So with the ram in (tried 3 different sticks, they were mounted during the chrash though) i get 1 long 3 fast beeps.

Without any memory seated i get repeat of one long beep.

I cannot remeber what bios this board has. It has a fancy sticker stuck to one of the ISA ports that says "award" Dont know if that referrs to the bios or not.
That would suggest that its a video card problem, however if its AMI bios then the fault code is for RAM.

Edit: The fault code is the same with or without the video-card, but i guess that RAM check comes first.
« Last Edit: January 02, 2020, 06:19:23 pm by spilihps »
 

Offline madao

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Re: Broken IC on old Pentium 2 motherboard
« Reply #66 on: January 02, 2020, 06:29:46 pm »
Did you know  manufacture or modell of motherboard?

Pentium 2 era , award bios is common. I have never seeing  Penitum II /III computer with AMI bios. Phoenix bios is a niche.


Pentium II motherboard with  440BX chipset is my farvoit board, i have use it long (at frist old slot1 with 440BX and Celeron 333A @ 500. Later use i Asus CUBX with Pentium III 1Ghz )

Greetings
matt
« Last Edit: January 02, 2020, 06:33:35 pm by madao »
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #67 on: January 02, 2020, 06:33:16 pm »
Actually i cannot find any manufacturer name on it, its just "INTEL-BX-B" So hard to tell..

Wonder if the video card died during or because this also then? It has 5 tantalum capacitors on it
 

Offline madao

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Re: Broken IC on old Pentium 2 motherboard
« Reply #68 on: January 02, 2020, 06:42:38 pm »
Have you ISA / PCI  graphics card?
Try with it.

Oh, Intel-BX-B is too simple name for motherboard.  Why  have i right guess, it have 440BX.  8)

 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #69 on: January 02, 2020, 06:48:44 pm »
Yeah, i will see if i have another grahic card, my suspicion is that i dont have another "1-slot" AGP nor any pci graphics on hand though
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #70 on: January 02, 2020, 06:55:38 pm »
http://rayer.g6.cz/hardware/postcard.htm google should be able to translate this
all you need is address decoding to trigger on 80h writes and a latch to catch the value, you can either output to 8 led array or read it with logic analyser, better yet if your LA is 16 bit just wire it up to 8 data bits, IOW pin and couple address bus pins including A7 for partial address decode, enough to catch all 80h port writes, we are mostly interested in the last one anyway

but I would try another graphic card first
BTW another way to see if cpu is running is clicking CAPS/SCROLL/NUM LOCK and looking at the keyboard LEDs, this operation is done 100% in software

nevermind, I see you confirmed running CPU :)

https://i.ebayimg.com/images/g/BHYAAOSwl8ZdX~JJ/s-l1600.jpg WTF is this brand?
at lest I can confirm bios is Award
edit:
FYI (Full Yes) 82440BX   03/01/1999-i440BX-SMC60X-2A69KF39C-00   INTEL-BX VER:B_1.2
FYI (Full Yes Industrial)

another example of FYI board https://pc.watch.impress.co.jp/docs/article/980603/fyi1.jpg from COMPUTEX TAIPEI 98 expo https://translate.google.com/translate?hl=en&sl=ja&u=https://pc.watch.impress.co.jp/docs/article/980603/cmptx0.htm&prev=search
white dim slots and overal design are quite a tell
« Last Edit: January 02, 2020, 07:12:34 pm by Rasz »
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #71 on: January 02, 2020, 07:58:53 pm »
http://rayer.g6.cz/hardware/postcard.htm google should be able to translate this
all you need is address decoding to trigger on 80h writes and a latch to catch the value, you can either output to 8 led array or read it with logic analyser, better yet if your LA is 16 bit just wire it up to 8 data bits, IOW pin and couple address bus pins including A7 for partial address decode, enough to catch all 80h port writes, we are mostly interested in the last one anyway

but I would try another graphic card first
BTW another way to see if cpu is running is clicking CAPS/SCROLL/NUM LOCK and looking at the keyboard LEDs, this operation is done 100% in software

nevermind, I see you confirmed running CPU :)

https://i.ebayimg.com/images/g/BHYAAOSwl8ZdX~JJ/s-l1600.jpg WTF is this brand?
at lest I can confirm bios is Award
edit:
FYI (Full Yes) 82440BX   03/01/1999-i440BX-SMC60X-2A69KF39C-00   INTEL-BX VER:B_1.2
FYI (Full Yes Industrial)

another example of FYI board https://pc.watch.impress.co.jp/docs/article/980603/fyi1.jpg from COMPUTEX TAIPEI 98 expo https://translate.google.com/translate?hl=en&sl=ja&u=https://pc.watch.impress.co.jp/docs/article/980603/cmptx0.htm&prev=search
white dim slots and overal design are quite a tell

The first image seem to be exactly my board!

I managed to find a box full of old parts, and a AGP card! The card now works FINALLY!!!!
So all the ram and cpu survived, but the graphics card died.

I know that it died the same second as the IC, because i was using it at the time.
Rasz, are you up for another thread, trying to repair the graphic card?  :-DD :-DD :-DD

Also i want to thank everyone that chipped with knowledge on this, and extra special thanks to Rasz for all your knowledge regarding these old board.
 

Offline magic

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Re: Broken IC on old Pentium 2 motherboard
« Reply #72 on: January 02, 2020, 09:01:09 pm »
It probably was the 12V rail that killed this regulator. So insert the card and find with continuity tester where 12V goes on the card.

Probably another regulator. If you are lucky it may even have a hole in it ;)
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #73 on: January 02, 2020, 11:04:42 pm »
It probably was the 12V rail that killed this regulator. So insert the card and find with continuity tester where 12V goes on the card.

Probably another regulator. If you are lucky it may even have a hole in it ;)

Well I don't seem so lucky!

The card does not seem to have so much intelligent chips on it besides the main CPU. And after a quick glance the AGP 12v trace just goes straight up to some sort of expansion header.. not sure if it even uses 12v?

There is one chip with the name REG1 TL431 it has:
3.3v on pin 1 and 2.5 on pin 8

 

Offline madao

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Re: Broken IC on old Pentium 2 motherboard
« Reply #74 on: January 03, 2020, 03:41:32 am »
 |O  ATI RAGE..... i hate him,  driver problem (instabilty & wrong color) make me to much rage !

This was why, i swapped stealhy this card with Matrox G200 cards on shool 20 years ago.

Old AGP card use directly 3.3V, no voltage regulator.
TL431 is reference voltage regulator, it is too weak for power application.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #75 on: January 03, 2020, 03:22:33 pm »
 Thanks for your input,

Yeah then we probably saw overvoltage on that rail too.. it points more and more towards the PSU..

Guess the card is scrap then
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #76 on: January 03, 2020, 06:01:09 pm »
Oh, and also, are you guys aware if  there are any PCI / ISA "blank cards" that one could use for hooking up a logic analyzer to a motherboard? That would be a cool project to see if the graphiccard "boots" at all. because its not every time that i get the beep, sometimes it just seem to freeze.
« Last Edit: January 03, 2020, 06:04:44 pm by spilihps »
 

Offline GromBeestje

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Re: Broken IC on old Pentium 2 motherboard
« Reply #77 on: January 03, 2020, 06:24:18 pm »
 

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Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #79 on: January 05, 2020, 07:11:34 pm »
You cant snoop on AGP bus by sniffing ISA/PCI ones.
That video you send me


I would start with cmos reset. Does it detect hard drives at all when plugged? does hdd autodetect work in the bios? have you plugged and configured fdd? does it blink/run its motor looking for floppy? Southbridge is probably ok (its used to access BIOS), but Super I/O (SMSC chip) might be fried (rs232 buffer chips use 12V), or some random linear regulator also died somewhere. Wouldnt hurt reflashing bios.
Edit: wait, keyboard and cmos/rtc are in Super IO, so that must also work :/

ATI RAGE is indeed not worth fixing, they are worthless.
« Last Edit: January 05, 2020, 07:15:06 pm by Rasz »
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #80 on: January 05, 2020, 07:33:46 pm »
Thanks for your response,

CMOS reset is done. It recognize both HDD and cdrom, on both channels(swapped them around), it also identifies FDD, no problem. I've tried booting from floppy, HDD, cdrom separately. It does exact same thing.
One thing that sticks out is that when booting from floppy,  precisely when it stops in the video the FDD light turns on and stays on for ever.

Bios configuration works as normal,  I can set rtc, and so on.

Edit: I do have post card on the way, could this help with this, or is this error "after"?
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #81 on: January 06, 2020, 09:43:19 am »
This is past the post codes.
Disable everything not nailed down in the BIOS, unplug everything but cpu/ram/graphics/keyboard and see what happens. Might be half fried super I/O hanging on floppy detect. The very next thing after your hag should be clear screen followed by a table of all installed/configured elements, then list of PCI/PNP resources, some windows management nonsense update and finally HDD boot.

Does pressing numlock still control keyboard led after the hang?
« Last Edit: January 06, 2020, 09:53:49 am by Rasz »
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #82 on: January 06, 2020, 02:04:56 pm »
So I tried to disable all IDE and floppy, same thing.
Numlock works after it hangs, however after 5 toggles it seem to be disabled. The screen cursor blinks though.

I did notice however, the LED for HDD activity lights up (very dim) directly when power on.
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #83 on: January 06, 2020, 03:15:50 pm »
Everything, I mean every single choice that has none/disabled option, under all tabs.
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #84 on: January 06, 2020, 06:28:41 pm »
I think I got em all, yes!

Results in this screen, blinking cursor, numlock responds, and Ctrl+alt+del works
 

Offline Per Hansson

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Re: Broken IC on old Pentium 2 motherboard
« Reply #85 on: January 06, 2020, 07:00:44 pm »
Edit: I do have post card on the way, could this help with this, or is this error "after"?
This is past the post codes.
Actually you will have POST codes up until the BIOS passes over control to the bootloader.
In these screenshots you are at or around step 42:
http://www.bioscentral.com/postcodes/awardbios.htm
So yes, it could prove useful...
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #86 on: January 06, 2020, 07:15:32 pm »
Edit: I do have post card on the way, could this help with this, or is this error "after"?
This is past the post codes.
Actually you will have POST codes up until the BIOS passes over control to the bootloader.
In these screenshots you are at or around step 42:
http://www.bioscentral.com/postcodes/awardbios.htm
So yes, it could prove useful...

Thanks!

So maybe setting a password would show us if we get to 4F?
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #87 on: January 06, 2020, 08:00:17 pm »
It does not reach password  :scared:
 

Offline Per Hansson

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Re: Broken IC on old Pentium 2 motherboard
« Reply #88 on: January 06, 2020, 08:29:01 pm »
By deduction then it might be that you are stuck at 43: Detect & Init. serial & parallel ports
Or you are stuck at 42 Initialize hard drive
A hanging floppy lights usually means the cable is plugged in reversed.
But it can also be caused by more serious issues like BIOS not supporting the size of HDD and thus hanging.
In your case with what the board has been through it would be interesting to reflash the BIOS.
But I don't assume you have found a copy anywhere?

EDIT: Have you tried the board with no external stuff attached?
I.e. no floppy, HDD, mouse, keyboard and whatever add-in card you might have except the required stuff like RAM, CPU & Video card?
Because I found this based on the BIOS string posted earlier in the thread, a patched BIOS with support for up to 64GB HDDs.
This implies that the example I gave applies for you: i.e. it might be hanging because of overflow bug when detecting the size of the HDD:
http://wims.rainbow-software.org/index.php?start=90&count=50
« Last Edit: January 06, 2020, 08:34:47 pm by Per Hansson »
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #89 on: January 06, 2020, 08:39:34 pm »
Yeah and now everything is unplugged and serial / paralellports is disabled in bios.

A reflash would be interesting, but that would need to happen in a programmer I guess since the board won't boot. I do have a Willem programmer that is absolutely shit  :-DD

I might have another slot 1 board with a bios like this one, will have to check that out.

Thinking of it, one very interesting thing with this is that the IC blew up pretty much exactly at this point in the boot, it might have changed to the next screen though or the blacked out one in between.

Edit: idk if that board is capable of flashing itself?
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #90 on: January 06, 2020, 11:17:44 pm »


EDIT: Have you tried the board with no external stuff attached?
I.e. no floppy, HDD, mouse, keyboard and whatever add-in card you might have except the required stuff like RAM, CPU & Video card?
Because I found this based on the BIOS string posted earlier in the thread, a patched BIOS with support for up to 64GB HDDs.
This implies that the example I gave applies for you: i.e. it might be hanging because of overflow bug when detecting the size of the HDD:
http://wims.rainbow-software.org/index.php?start=90&count=50

Thanks for all your help!

Sorry, i did not see your edit before.

Yes, i dont have anything then ram cpu and video attached. Even tried to disable halt on keyboard error, and tried to boot witout keyboard.
Also, the harddrive is well within the limits though.
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #91 on: January 07, 2020, 10:02:47 am »
Edit: I do have post card on the way, could this help with this, or is this error "after"?
This is past the post codes.
Actually you will have POST codes up until the BIOS passes over control to the bootloader.
In these screenshots you are at or around step 42:
http://www.bioscentral.com/postcodes/awardbios.htm
So yes, it could prove useful...

You are correct, how did I miss that :(
Looks like it might be either Super IO or CPU (math coprocessor init)?
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Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #92 on: January 07, 2020, 11:26:33 am »
I have a p2 CPU on the way, should be here soon, will drop that in.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #93 on: January 20, 2020, 05:20:43 pm »
Finally the post cards have arrived!

I bought two different, since they are from china after all!

One is 4 digit and one is two digit.

The 4 digit stops at 5251 and the two digit stops at 52.

Guess the 4 digit is previous code or something?

52 is "Initialize option ROM's; Initialize and ROM's present at locations C800h to EFFFFh"

option ROM being?
 

Offline Per Hansson

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Re: Broken IC on old Pentium 2 motherboard
« Reply #94 on: January 20, 2020, 06:27:16 pm »
Yes, the 4 digit post card shows both the current and previous post code.
Option ROM is external device, but it can be built into the mainboard also.
For example: network card PXE boot, SCSI or SATA or IDE RAID device.
Did you receive a new CPU to test with yet?
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #95 on: January 20, 2020, 06:42:37 pm »
Yes, the 4 digit post card shows both the current and previous post code.
Option ROM is external device, but it can be built into the mainboard also.
For example: network card PXE boot, SCSI or SATA or IDE RAID device.
Did you receive a new CPU to test with yet?

Thanks, actually i did recieve another one SL2S6 (SL2WZ is the one original with the board) however i may have recieved a broken one. Board wont boot at all with it. Also code "00" now trying it with the POST-card.
Not having any luck with this. :-DD Maybe some compatibility issues?
 

Offline PKTKS

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Re: Broken IC on old Pentium 2 motherboard
« Reply #96 on: January 20, 2020, 07:00:26 pm »
Finally the post cards have arrived!
I bought two different, since they are from china after all!
One is 4 digit and one is two digit.
The 4 digit stops at 5251 and the two digit stops at 52.
Guess the 4 digit is previous code or something?
52 is "Initialize option ROM's; Initialize and ROM's present at locations C800h to EFFFFh"
option ROM being?


 *** IF **
- This is an Award BIOS
- And the POST paused at 52 (Option ROM)
- and the board has Ethernet integrated  (onboard)

My first  guess at that range (C800h ~ )  would be Ethernet ROM BIOS

several other problems may be plausible for that stuck WITHOUT onboard
Ethernet chipset - including corrupted  BIOS itself

A BIOS REFLASH would be my next step in that case
Paul

 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #97 on: January 20, 2020, 07:12:26 pm »
Finally the post cards have arrived!
I bought two different, since they are from china after all!
One is 4 digit and one is two digit.
The 4 digit stops at 5251 and the two digit stops at 52.
Guess the 4 digit is previous code or something?
52 is "Initialize option ROM's; Initialize and ROM's present at locations C800h to EFFFFh"
option ROM being?




 *** IF **
- This is an Award BIOS
- And the POST paused at 52 (Option ROM)
- and the board has Ethernet integrated  (onboard)

My first  guess at that range (C800h ~ )  would be Ethernet ROM BIOS

several other problems may be plausible for that stuck WITHOUT onboard
Ethernet chipset - including corrupted  BIOS itself

A BIOS REFLASH would be my next step in that case
Paul

Thanks, interesting,

The board does not have onboard ethernet. 

Reflash through a external programmer then? If i could get hold of a image then that would be possible, but that is a long shot in this case i think.
« Last Edit: January 20, 2020, 07:15:59 pm by spilihps »
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #98 on: January 20, 2020, 07:17:47 pm »
I remember re-flashing BIOS chips back in the day with my Willem programmer and a firmware hub adapter I built, I think it was my first successful self etched PCB. Anyway finding a bios image might not be that hard if it's a reasonably common board. You might be able to find one from the manufacture using wayback or if you post the model of the board someone who has one could dump their own. It's even possible that a bios from a similar board will work.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #99 on: January 20, 2020, 07:22:45 pm »
Yeah, i actually had a Willem programmer for some Z80 experiements. But it was very unreliable so i discarded it.
But iam thinking of getting a new one for my 68000 projects pretty soon, so that would not be a problem.

The board does not seem to have a real manufacturer marking on it for some reason. Thinking of it.. I seem to remeber when i recieved this PC as a gift in about 1998 i think...
The box for the motherboard may have said "Mainboard Mentor" on it. But not much to go on..
 

Offline Per Hansson

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Re: Broken IC on old Pentium 2 motherboard
« Reply #100 on: January 20, 2020, 07:56:21 pm »
I have already linked you a BIOS for your board in post #88.

This is based on the BIOS string you have posted in your images.
Rasz showed you in post #70 that the manufacturer is: FYI (Full Yes Industrial) based on your BIOS string.
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #101 on: January 20, 2020, 07:58:23 pm »
I use a TL866 now in place of the old Willem I had, I'm pretty sure it will handle most bios chips.

Looks like someone already found you the bios, lacking that I would experiment with others from similar boards and see if any of them work.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #102 on: January 20, 2020, 08:04:36 pm »
I have already linked you a BIOS for your board in post #88.

This is based on the BIOS string you have posted in your images.
Rasz showed you in post #70 that the manufacturer is: FYI (Full Yes Industrial) based on your BIOS string.

Oh sorry, i forgot that. The thread is getting quite long!
Thank you very much for your input.

I use a TL866 now in place of the old Willem I had, I'm pretty sure it will handle most bios chips.

Looks like someone already found you the bios, lacking that I would experiment with others from similar boards and see if any of them work.

Yeah that is the one im looking to get!
 

Offline PKTKS

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Re: Broken IC on old Pentium 2 motherboard
« Reply #103 on: January 21, 2020, 10:57:38 am »
(..)
Reflash through a external programmer then? If i could get hold of a image then that would be possible, but that is a long shot in this case i think.

Yes outside the board w/proper BIOS checking if the
chipset still holds the new data.

TL866 or RT809 both will do the trick
https://www.aliexpress.com/item/33000308958.html
https://www.aliexpress.com/item/33003747546.html

Paul
 

Offline PKTKS

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Re: Broken IC on old Pentium 2 motherboard
« Reply #104 on: January 21, 2020, 02:25:52 pm »
For the record...

If you ask me which one (today) I would rather prefer...

Just a few years ago you would be cursing that closed source
press button pile of garbage from last decades...

No longer the case ... MiniPro works absolutely fine
under WINE with just the minor glitches of MS poorly
inter-operational toolkit UI (just UI fonts.)

Otherwise.. go plain console from SOURCE which
in any case works perfect

https://gitlab.com/DavidGriffith/minipro/

Paul
« Last Edit: January 21, 2020, 03:15:01 pm by PKTKS »
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #105 on: January 21, 2020, 06:41:16 pm »
(..)
Reflash through a external programmer then? If i could get hold of a image then that would be possible, but that is a long shot in this case i think.

Yes outside the board w/proper BIOS checking if the
chipset still holds the new data.

TL866 or RT809 both will do the trick
https://www.aliexpress.com/item/33000308958.html


For the record...

If you ask me which one (today) I would rather prefer...

Just a few years ago you would be cursing that closed source
press button pile of garbage from last decades...

No longer the case ... MiniPro works absolutely fine
under WINE with just the minor glitches of MS poorly
inter-operational toolkit UI (just UI fonts.)

Otherwise.. go plain console from SOURCE which
in any case works perfect

https://gitlab.com/DavidGriffith/minipro/

Paul

https://www.aliexpress.com/item/33003747546.html

Paul

Thank for your help and input!

Its also great to see how far Wine have come.. Remembering using it way back in 2005-2006 maybe. It could be a hassle sometimes :)

The TL866 unit seems great, there are many that give it good feedback.
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #106 on: January 21, 2020, 06:49:49 pm »
Wine can still be a hassle, but for a lot of things it really works pretty well. For years I tried Linux every couple of years, marveled at how much it had improved but then soon hit some kind of show stopper and set it aside, then finally a few years ago I found it had reached a point where aided by the regression in polish and quality that Windows suffered, it was finally looking really good.

I do wish the MiniPro GUI software was open source in the first place though, then at least we could fix the chinglish. The software doesn't live up to the quality of the device and drags down the overall experience but it's still quite good and a bargain for the price.
 

Offline PKTKS

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Re: Broken IC on old Pentium 2 motherboard
« Reply #107 on: January 22, 2020, 10:57:34 am »
Wine can still be a hassle, but for a lot of things it really works pretty well. For years I tried Linux every couple of years, marveled at how much it had improved but then soon hit some kind of show stopper and set it aside, then finally a few years ago I found it had reached a point where aided by the regression in polish and quality that Windows suffered, it was finally looking really good.

I do wish the MiniPro GUI software was open source in the first place though, then at least we could fix the chinglish. The software doesn't live up to the quality of the device and drags down the overall experience but it's still quite good and a bargain for the price.

Pretty much WINE "just works" for reasonable written applets.

For those ones bundled with underlying "licenses" and "rights"
your mileage will surely vary.

For TL866 this folk made a decent job (ditching the original MiniPro for good)
by using a nice QT interface to handle the device firmware itself

Check https://github.com/radiomanV/TL866
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #108 on: January 23, 2020, 03:49:27 pm »
So i have pulled the old flash chip,
28F1000PPC-12C4, i was thinking that it might be a good idea to have a replacement chip, since this died at the same time as the other components.

Is there compatible replacements available from a good source like Mouser?

In my other motherboard thread (Seems to be in a mobo rescue streak right now :)), i needed the SST39F020, that has more memory capacity than this one. (They do have the 010 variant also)

Would it by any chance be compatible?

Its not so easy to compare these memory chips :)
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #109 on: January 23, 2020, 04:42:54 pm »
It ought to be easy, the datasheet is readily available.

https://www.alldatasheet.com/view.jsp?Searchword=28F1000PPC&sField=1

Looks at a glance like a 128k x8 flash  eeprom. I'm on my phone at the moment so I'm not going to try to study the datasheet but it ought to tell you everything you need. A larger part may work but in that case you'd probably want to concatenate multiple copies of the firmware to fill it.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #110 on: January 23, 2020, 04:53:43 pm »
It ought to be easy, the datasheet is readily available.

https://www.alldatasheet.com/view.jsp?Searchword=28F1000PPC&sField=1

Looks at a glance like a 128k x8 flash  eeprom. I'm on my phone at the moment so I'm not going to try to study the datasheet but it ought to tell you everything you need. A larger part may work but in that case you'd probably want to concatenate multiple copies of the firmware to fill it.

Yeah the 010 variant is the same size at least, and pin compatible.. but I don't know if there are other pit falls?
 

Offline Bud

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Re: Broken IC on old Pentium 2 motherboard
« Reply #111 on: January 23, 2020, 05:46:22 pm »
Yeah, i actually had a Willem programmer for some Z80 experiements. But it was very unreliable so i discarded it

Two mods make Willem perform like a tank:
-replace the parallel port input buffers to Schmitt input buffers
-increase programming power supply current

mine was ok when used with the desktop but flaky when used with a laptop. It also did not burn properly big ROMs. It is now flwaless from the laptop through a 15 feet parallel cable and burns everything i throw at it from 27c16 to 27c1000 (the biggest UV eraseable  ROM i have) and just couple days ago programmed a 512kB flash.
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Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #112 on: January 23, 2020, 09:09:45 pm »
With the wrong chip you might have trouble trying to update the bios through the motherboard but as long as the pinout and voltage are the same it should work.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #113 on: January 24, 2020, 08:38:31 pm »
With the wrong chip you might have trouble trying to update the bios through the motherboard but as long as the pinout and voltage are the same it should work.

Thanks James for your input.
I can live without not being able to program from the board. Rather that then gamble on all the fake chips on ebay.. :)
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #114 on: January 25, 2020, 05:41:27 am »
eprom chips from ebay wont be fake, at worst you will get pulls from ewaste, nothing wrong with those
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Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #115 on: January 25, 2020, 08:07:19 pm »
That may be true of windowed eproms but the sort you'd find in a square 32 pin package used in motherboards of this era are forms of eeprom and will not have a quartz window, I've been burned by fake eeproms multiple times that were either mask or OTP ROMs with data already on them or something else entirely. Any part can be fake, the quartz window of traditional eproms just makes it a lot easier to tell what you're actually getting.
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #116 on: January 25, 2020, 08:29:36 pm »
Also, the ones on eBay are actually quite expensive compared to the new ones from mouser..
So I figured if there is a chance for them to work as a replacement I will give them a shot..

eBay is around 10€ each and mouser is about 1,2€ each
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #117 on: March 26, 2020, 06:20:40 pm »
So at last an update to this never ending story!

I received my new EEPROM actually found the same part 28F1000, and burned the new firmware on to one of them, bought three just in case.

But a new problem arise! Of course!

Now we only get to code 31 (Wich is check RAM) The interesting thing here, is that it does not begin counting the ram, neither does it even show the text line, it just sits there and blinks the cursor on the line after "PENTIUM II CPU at 350MHz"

The only "Life" after that is that after maybe 2 seconds the "IRDY" LED on the post-card goes out.

Now, i tried to dump the old ROM and burn that one. And then we get the same exact behavior as we did with the old rom (Just did this to check the programmer) it counts the ram and such.
So now im not sure if the .BIN file from that site is botched, or we got something else wrong with the card? Cannot find any other bios file though.


******************UPDATE 2:

So guys, you wont believe this.

A while back i bought a new P2 350mhz (SL2S6) to try the board out with. When i plugged that in, nothing happened, so i thought it was maybe a dud, since the seller was kind of sketchy.

And just for the fun of it, i plugged it in with the new ROM, guess what, the board boots in to Win95, but the cpu only register as 300mhz..

I cannot believe whats going on here?

Maybe wrong case on the CPU, and that i have both a dead CPU and original ROM?


Also, i get "Unknown Flash type" before "Starting Windows 95".

****************UPDATE 3:

So yes, the case was replaced on the CPU, after lifting it i found the SL2QV chip, seem to be only for the 300mhz.. GEES.

So i guess i had a _partly_ broken CPU and _partly_ broken EEPROM?
« Last Edit: March 26, 2020, 08:56:34 pm by spilihps »
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #118 on: March 27, 2020, 03:00:14 am »
Yay!  :clap:
cpu was suspect from the start due to fried regulator
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Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #119 on: March 27, 2020, 05:08:30 am »
That wouldn't surprise me at all. If the regulator failed such that you got excessive voltage on the CPU it could have easily damaged all sorts of stuff. Sounds like you lucked out, thanks for the followup and success story, you ought to really know your way around early 2000's PC motherboards at this point, for whatever that's worth.
 

Offline Per Hansson

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Re: Broken IC on old Pentium 2 motherboard
« Reply #120 on: March 27, 2020, 06:15:03 am »
Great perseverance!
Strange that the board did not POST at all with the new eBay CPU with the original ROM.
But that it works fine now with the new ROM.
Well, I guess it could have been unsupported with the original ROM?

As for the CPU speed you set that with jumpers on the board.
If you don't have the manual I found the attached quick reference.
The number you posted is not a sSPEC but a part number for the CPU's TagRAM.
I would be surprised if someone made a counterfeit P2 CPU in 2020, let alone to cheat 50Mhz ;)
 

Offline Rasz

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Re: Broken IC on old Pentium 2 motherboard
« Reply #121 on: March 27, 2020, 06:21:02 am »
Great perseverance!
Strange that the board did not POST at all with the new eBay CPU with the original ROM.
But that it works fine now with the new ROM.
Well, I guess it could have been unsupported with the original ROM?

I bet that was coincidence, it should totally work

As for the CPU speed you set that with jumpers on the board.

locked multipliers on that cpu gen, fsb auto detected with B21 pin

The number you posted is not a sSPEC but a part number for the CPU's TagRAM.
>TagRAM chip mounted on the back of Pentium II Slot 1 processor (300 MHz)

I would be surprised if someone made a counterfeit P2 CPU in 2020, let alone to cheat 50Mhz ;)
more like someone dug it out of garbage in china and slapped whatever cooling was around
Who logs in to gdm? Not I, said the duck.
My fireplace is on fire, but in all the wrong places.
 

Offline Per Hansson

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Re: Broken IC on old Pentium 2 motherboard
« Reply #122 on: March 27, 2020, 06:24:05 am »
Okay cool, yea it was many years ago that the P2 was the king of the hill so maybe my memory does not serve me ;)
 

Offline spilihpsTopic starter

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Re: Broken IC on old Pentium 2 motherboard
« Reply #123 on: March 29, 2020, 06:06:59 pm »
Yay!  :clap:
cpu was suspect from the start due to fried regulator

Yeah it was! I did however have hopes for it since it counted all the ram, and worked fine scrolling through the bios settings. I in my naive mind thought that it either works or dont when it comes to a CPU :)

So this resulted in two casualties CPU and the GPU. Wonder if they are repairable?  :scared:

All due to a temporary overvoltage from the PSU i guess then.

Thank you very much for your help and input, and keeping up with me during all the confusion haha!

That wouldn't surprise me at all. If the regulator failed such that you got excessive voltage on the CPU it could have easily damaged all sorts of stuff. Sounds like you lucked out, thanks for the followup and success story, you ought to really know your way around early 2000's PC motherboards at this point, for whatever that's worth.

Yeah, i think everything started out with a temporary overvoltage from the PSU.
Also, thank you for your help and input!

At least i know my way around this particular board now. Probably not worth much when it comes to knowledge haha!
Great perseverance!
Strange that the board did not POST at all with the new eBay CPU with the original ROM.
But that it works fine now with the new ROM.
Well, I guess it could have been unsupported with the original ROM?

As for the CPU speed you set that with jumpers on the board.
If you don't have the manual I found the attached quick reference.
The number you posted is not a sSPEC but a part number for the CPU's TagRAM.
I would be surprised if someone made a counterfeit P2 CPU in 2020, let alone to cheat 50Mhz ;)

Thanks Per for all your help with this also, everyone have been great. I did so much testing and tinkering i lost my self at times  :phew:

And also the other CPU, i have no idea. And i still dont understand why the original CPU counts the ram OK with original roms, but cannot start the boot process. And that it dont even get to the memory count with the new ROM file.
 

Offline james_s

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Re: Broken IC on old Pentium 2 motherboard
« Reply #124 on: March 30, 2020, 01:50:44 am »
And also the other CPU, i have no idea. And i still dont understand why the original CPU counts the ram OK with original roms, but cannot start the boot process. And that it dont even get to the memory count with the new ROM file.

It all depends on just what is wrong with it, if you really wanted to go down that rabbit hole then I would suggest looking at each of the address and data lines with a scope or logic analyzer. If you have for example one address line that is stuck then it will cause some addresses to appear at the right place while others could be accessing something completely wrong. The difference between the BIOS ROMs could be as simple as some instruction pointing to memory in a slightly different location. I suspect something like this is what you have happening, one damaged address pin which is not involved in reading the code used by the memory test.
 


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