Author Topic: What more i can do?  (Read 36951 times)

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Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #325 on: November 26, 2024, 04:12:17 am »
Also please do the following.
Don't touch DIP switches but only measure and compare the voltages.

SW2 and SW4

Its High Voltages 5V
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #326 on: November 26, 2024, 04:18:34 am »
Please print a traces from OE at the same scale.
Working ang non-working
ITS HERE
 

Offline Harry_22

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Re: What more i can do?
« Reply #327 on: November 26, 2024, 06:25:47 am »
Make a photo of EPROMs including Dip switches of both boards
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #328 on: November 26, 2024, 06:42:04 am »
Make a photo of EPROMs including Dip switches of both boards
Good
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #329 on: November 26, 2024, 06:43:04 am »
Bad
Only difference is Bad board SW4  4 pin is changed because it is the beep one, If it is turn on it keep beeping so
 

Offline Harry_22

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Re: What more i can do?
« Reply #330 on: November 26, 2024, 07:02:16 am »
Have you checked them from both sides? SW2 also has different positions
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #331 on: November 26, 2024, 07:13:12 am »
Have you checked them from both sides? SW2 also has different positions
SW2 is fine, SW2 3rd PIN is HIGH other are LOW.
Whereas SW4 all PIN are HIGH. BUT if there is beep i need to turn off so 4th PIN is set LOW.
 

Offline Harry_22

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Re: What more i can do?
« Reply #332 on: November 26, 2024, 07:38:18 am »
Have you checked them from both sides? SW2 also has different positions
SW2 is fine, SW2 3rd PIN is HIGH other are LOW.
Whereas SW4 all PIN are HIGH. BUT if there is beep i need to turn off so 4th PIN is set LOW.
Don't trust your eyes.
Have you measured them?
 

Offline Harry_22

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Re: What more i can do?
« Reply #333 on: November 26, 2024, 03:17:19 pm »
Resume
Tracing the Q0 (Data) signal you can see that the no-good (NFG) board goes only through seven identical clock cycles with the good board. Please see below all the traces from NFG and the Good boards.

I suspect that one Data or Address signal is corrupted.
To clarify this please measure all the lines of Address (0...17) and Data (0...15) buses (sorry I have no ideas for today).
I suggest you do a manual reset to make measurements easier.
Please see the attached picture.

If you doubt the shape of the signal, look it on the working board.

« Last Edit: November 26, 2024, 08:44:41 pm by Harry_22 »
 

Offline Poroit

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Re: What more i can do?
« Reply #334 on: November 27, 2024, 07:53:37 am »
G'day All,

It looks like the fault finding is Bogging Down. :(

I have attached a summary of Replies that I cannot see were resolved. Kindly review and advise.

I emailed Jotrin yesterday for a WE001BF Datasheet after chatting to WACOM but I won't hold my breath waiting.




 

Offline Harry_22

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Re: What more i can do?
« Reply #335 on: November 27, 2024, 09:55:35 am »
OP, you found out that the board has battery powered SRAM a week ago and didn't say anything.
I would like you to be more attentive.

Here we must take into account the nature of the malfunction and pay special attention to bottlenecks.
Although I am not sure that the SRAM is activated at the beginning of loading.
On a similar machine this 24-pin SRAM is located next to the EPROM.
« Last Edit: November 27, 2024, 07:23:40 pm by Harry_22 »
 

Offline CaptDon

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Re: What more i can do?
« Reply #336 on: November 27, 2024, 01:27:11 pm »
Anyone feel like this thread will go to 28 pages and the unit still not work?
Collector and repairer of vintage and not so vintage electronic gadgets and test equipment. What's the difference between a pizza and a musician? A pizza can feed a family of four!! Classically trained guitarist. Sound engineer.
 
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Offline PA0PBZ

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Re: What more i can do?
« Reply #337 on: November 27, 2024, 03:13:26 pm »
It looks like the OP has lots of boards with the same error: "I have lots of those boards with 99% having the error of beep" so maybe it would be a good idea to send some out to people that could maybe diagnose the problem?
Keyboard error: Press F1 to continue.
 

Online fzabkar

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Re: What more i can do?
« Reply #338 on: November 28, 2024, 01:21:06 am »
OP, you found out that the board has battery powered SRAM a week ago and didn't say anything.
I would like you to be more attentive.

Here we must take into account the nature of the malfunction and pay special attention to bottlenecks.
Although I am not sure that the SRAM is activated at the beginning of loading.
On a similar machine this 24-pin SRAM is located next to the EPROM.

I think the OP and I are somewhat overwhelmed. That other thread at Reddit was a dead end. I took the OP down the wrong track because I was convinced that expensive industrial equipment, for which downtime is critical, would have a diagnostic port to facilitate rapid fault finding by a field tech. In fact, I didn't want to get involved here because I didn't want to pollute this discussion with remnants from the other.

I think you're doing a great job, given the lack of documentation and the time delay. I'm wondering at which point the BIOS code stops executing. At some time early in the POST, the BIOS must compute a checksum over its contents. This means it needs to read 512K bytes at a clock rate of 66MHz. That's at least 512K instructions, with a 15ns clock. If EPROM access comes to a halt before the checksum routine can start, then perhaps that will tell us something.
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #339 on: November 28, 2024, 02:07:25 am »
OP, you found out that the board has battery powered SRAM a week ago and didn't say anything.
I would like you to be more attentive.

Whats the thing with SRAM? Sometimes there is lots of comments and i may miss some messages of comments sometimes.
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #340 on: November 28, 2024, 02:11:15 am »

I have attached a summary of Replies that I cannot see were resolved. Kindly review and advise.


"After couple of weeks test here and there, i somehow find that those MSDOS are not getting input
address bus voltages.
A16 and A17 "

Thats the main cause why i started this thread.
 

Offline Harry_22

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Re: What more i can do?
« Reply #341 on: November 28, 2024, 02:17:20 am »
fzabkar, no problem. Don't you know that when troubleshooting, many times you have to take the wrong path. But this is how knowledge is acquired.
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #342 on: November 28, 2024, 02:29:16 am »
I also somehow feel that there is no issues in BIOS or the BIOS slot, You may say it as a instinct because even if i swap BIOS, the non working board BIOS works in other working board.

And regarding the slots of BIOS not getting power, even if the BIOS are not put in the slots, the slots must get the power.(From Working Board)
Where it does get power?
-From the WACOM Tornado IC.

So i think there is no more points if we dig further regarding BIOS things, except than reading the BIOS from Universal Programmer (It will take more time, sorry). BUT if you guys want more digging on this BIOS things we can dig more, of course i am interested in solving board so no worries.

Now what i am actually thinking or been trying is, how is the WACOM IC work, as all revolve around this IC. I am wondering whats the things that this IC is receiving, and what is it triggered by to perform it usually.


Another another things i am worried is the blink of Green LED. WHY?
--In non working board, it blinks sometimes and it doesn't blink sometimes. Does it affect?
--Of course it affect, the glow and doesn't glow of green LED makes a power difference in ICs like IC 53  2nd PIN. If LED grow there is POWER and if LED doesn't grow, no power, which may affect how this IC performs.

GREEN LED is getting power from IC5 PIN4, and resistance R26. IC5 is under the BIOS Low.

Still I thank you for all your supports until now, especially Fzabkar and Harry22 for so much help on it.
And sometimes as i said, i forgot the comments so if you guys not getting the answer of questions you ask, Please Kindly ask again.
 

Offline Harry_22

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Re: What more i can do?
« Reply #343 on: November 28, 2024, 02:30:25 am »
Anyone feel like this thread will go to 28 pages and the unit still not work?
Oh, I didn’t think I’d be writing this here. It turns out that it is not only in my village that it is customary to attack others. Only here it happens in a polite manner.
What kind of betting are you running here?
CaptDon and PA0PBZ and BILLPOD and Analog Kid and ...
https://youtu.be/LLujpdPElPc?si=_gAz4qQeL9xGRzZJ
« Last Edit: November 28, 2024, 05:40:42 am by Harry_22 »
 
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Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #344 on: November 28, 2024, 02:37:18 am »
Anyone feel like this thread will go to 28 pages and the unit still not work?
I do not mind going to 100 no more than 1000 pages and still not work.
-Why? Because I am total beginner, yeah in one hand i want to solve this board BUT on the other hand i want to learn, I want to go deep on this electronics things. I want to understand more about this signals things like Harry_22 is doing. I want to understand how fzabkar is understanding how board is running without the Datasheet and Schematic.

If anyone look from my side, i am so happy that i meet this two guys, who are helping me to broaden my views on Electronics.
 

Offline Poroit

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Re: What more i can do?
« Reply #345 on: November 28, 2024, 05:22:48 am »
G'day All,

222Lab_Test222,Harry_22, fzabkar you are all doing a great job trying to fault find this PCB. Please keep it up :-+

You other Guys need to reread the Forum Rules.

"Regulars, please be extra nice to beginners asking questions. Do not deride them for anything, if you can't be nice, don't post.""

Att: PA0PBZ.....suggest who he could send them to!



 

Offline Harry_22

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Re: What more i can do?
« Reply #346 on: November 28, 2024, 04:52:58 pm »
Hello Collegues!


222Lab_Test222, would you see what happens when the machine starts:

1. The Reset# signal is removed.
This occurs 200ms after the supply voltage and clock signals are established.

2. The processor begins initialization and loading the BIOS program.
"The Intel486 OX microprocessor will start executing instructions at location FFFFFFFOH after RESET.
When the first InterSegment Jump or Call is executed, address lines A20-A31 will drop LOW for CS-relative memory cycles, and the Intel486 OX microprocessor will only execute instructions in the lower
one Mbyte of physical memory. This allows the system designer to use a ROM at the top of physical memory to initialize the system and take care of RESETs." (Page 6-11 of Intel486_DX2_Microprocessor_Data_Book_Jul92.pdf)

3. We have already traced the interaction of the processor with EPROM with the BIOS.
It goes like this. The processor sets the address and activates the Chip Enable#.
The Output Enable# clock reads data from the EPROM.
Then the address changes and the data is read again by OE#.

4. On the good machine you can see that after 20 microseconds CE# disappears and one more signal appears on the data bus from another device on the bus.

5. On a non-working machine, a fatal error occurs immediately after the seventh cycle if viewed on the D0 bus.
It should be noted that in a time period less than 3 μs from Reset# release , the processor initializes internal registers.

I missed one thing. You wrote:"Another another things i am worried is the blink of Green LED. WHY?
--In non working board, it blinks sometimes and it doesn't blink sometimes. Does it affect?"

This is very important. This is a result of unstable operation. The non-working machine loading every time has different breakpoint


Here, when diagnosing such a fault, we must remember that several boards have similar symptoms.
It follows that it could be a component like a capacitor that loses capacity over time. There may be a broken contact in the DIP switch. There may also be jamming of the CMOS memory due to low battery.
Knowing what reliable equipment was assembled in Japan at that time, I do not believe that this could be a chip malfunction.
Well, maybe specifically one with a built-in defect.
We have already looked at all possible options and now we are just looking at step-by-step loading. I am sure that we must find the problem. Even if you have to write down all the addresses and data and compare them with the contents of the EPROM.

222Lab_Test222, please make a manual reset button and view all the data and address signals on a non-working machine. We look for any deviation in amplitude, rise and fall fronts. If you have any doubts, print screenshots here and we’ll figure it out together.

PS
Yes, there are many more professionals here who can also express their assumptions.
Welcome everyone!
« Last Edit: November 28, 2024, 06:48:13 pm by Harry_22 »
 

Offline 222Lab_Test222Topic starter

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Re: What more i can do?
« Reply #347 on: November 29, 2024, 02:53:14 am »
Manual reset button, whats that and how can i made it?
 

Offline Poroit

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Re: What more i can do?
« Reply #348 on: November 29, 2024, 03:23:07 am »
G'day All,

Att: Harry _22.

I see your last post suggests the issue could be caused by:

1.Capacitor that loses capacity over time.
 
2.Broken contact in the DIP Switch.

3.Jamming of the CMOS memory due to low battery.

Att:222Lab_Test222

I suggest you change out all the caps and battery on one of the faulty boards so that they can be crossed off the list.

BTW.
I assume this Controller is linked to a Hydraulic Package that is used to steer the cutting head.

Can you send some pics of the Interface between the Controller and the Hydraulic package.

Thinking ahead...if this fault is due to a component that can no longer be sourced, you may be keen to build a new Controller using Raspberry Pi.








 

Offline Harry_22

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Re: What more i can do?
« Reply #349 on: November 29, 2024, 03:45:54 am »
I also encountered an atypical malfunction in old equipment from Rohde&Schwarz (Aviation transceivers). SMD resistors of certain values ​​break. There have already been several cases.
 


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