Broken IC on old Pentium 2 motherboard

[magic]

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

[Rasz]

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  ) 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

[pcmad]

i got lot of old  Pentium 2 motherboard if you need parts pm me

[james_s]

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

[NiHaoMike]

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.)

[spilihps]

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  ) 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 

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

Haha yes!

[spilihps]

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?

[pcmad]

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

[Rasz]

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!

[magic]

Beware that some keyboards blink by themselves when power is applied.

[spilihps]

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 
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.

[magic]

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.

[james_s]

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.

[spilihps]

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 

[james_s]

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.

[spilihps]

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.

[madao]

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

[spilihps]

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

[madao]

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. 

[spilihps]

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

[Rasz]

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

[spilihps]

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? 

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.

[magic]

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

[spilihps]

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

[madao]

   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.