(Topic ID: 214946)

Junk yard - problem with the audio/sound board and display


By jimy_speedt

1 year ago



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  • 13 posts
  • 3 Pinsiders participating
  • Latest reply 1 year ago by jimy_speedt
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#1 1 year ago

Hi,

I have a strange behaviour with the sound and display. Sometimes everything boots without problem, the display is as normal it plays properly.

At some time, I get problems with the display (horizontal lines, or dots, or even dark)

The display is new and works fine if I put it on another machine .
I replaced the ribbon cable from the A/S board, same problem
Then resoldered the J603 male connector and fuses support, same problem remains.

By looking at the audio board, I noticed that it sometimes boots properly Wwith the led 503 flickering. After a while, either the led becomes steadily lit, or dark (in which case the display becomes dark as well).

Can anyone bring some help ?

Thanks in advance

08CFA655-245B-4E37-951C-CBA154765E8F (resized).jpeg

#2 1 year ago
Quoted from jimy_speedt:

I replaced the ribbon cable from the A/S board, same problem

I guess you nean the narrow one from the A/V board to the DMD?

Reseat the two wide ribbon cables on both ends that go between the MPU and the A/V board.

#3 1 year ago

Just did it. The A/S led flashes once, then dark ...

#4 1 year ago

Can you post a really good picture of your MPU board just under the battery holder?

#5 1 year ago

Is this one ok ?

C2218F7A-948E-441A-8113-76EF0B262FD6 (resized).jpeg

#6 1 year ago

I see some alkaline corrosion on your battery holder terminals. Definitely, need a better picture as alkaline likes to get into the ground plane directly under the holder and spread like wildfire.

Maybe pull the MPU and press on the U9 ASIC chip with the board laying down flat on a table. If that does not help, can you test the MPU in another WPC95 game?

#7 1 year ago

got your message. I will remove the MPU and check if the board was damaged, yes there is alkaline. And unfortunately, I do not have another WPC95 to check. thanks a lot, I ll keep you posted if I find someone with whom I can swap boards.

1 week later
#8 1 year ago

The CPU is not damaged. I have replaced the ASIC but there is no better behaviour. Can it pe the CPU-A/S board flat cables ? anything else to check ?

#10 1 year ago

Thanks for your help, Inkochnito. This chip does not exist on wpc95 a/v board

By measuring outgoing voltages on the A/V board, I get -117vdc instead od of -125vdc on Pin1, -91vdc instead of -113vdc. I guess the difference might be bit too high to forget about it. No ? Should find wpc95 schematics

#11 1 year ago

Probably the best time to rebuild the HV section. Here are the parts required. https://www.greatplainselectronics.com/proddetail.asp?prod=WPC95-HVP-KIT

Quoted from jimy_speedt:

By looking at the audio board, I noticed that it sometimes boots properly Wwith the led 503 flickering. After a while, either the led becomes steadily lit, or dark (in which case the display becomes dark as well).

If you have a ColorDMD, you can try it in the game to be sure there is not another issue. Your description of the LED503 on the A/V board makes me question whether there is another issue on the board.

#12 1 year ago

Thanks PinballManiac, I ordered this rebuild kit. What you are writing to me confirms what I had read on the pinwiki link, also on the B/W repair guide.

3 weeks later
#13 1 year ago

I replaced the AV parts by a kit, and it works ! Thanks!!!

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