Arcade Collecting > Pinball
WPC sound board problem (A-12738)**FIXED**
lilshawn:
I got this Gilligan's Island machine on trade, everything works except the sound. The board was acting totally dead. No bongs on boot no static nothing.
all volts are there. ribbon cable good. EPROMS good (match 100% to bin file)...have a working board from another pin and it works fine. soooooo speakers and wiring are fine.
changed the amp chip, nothing still. changed the 2 74ls374 chips by the input of the data cable (u29 u30) and 2 op amps TL084 (u8 and u7 i believe) replaced the bridge diodes and caps just in case. still nothing.
i swapped the main cpu and the 2 yamaha chips from the working board and also a non-working board(with an unknown problem), and i can get some static noise (varies) and a few random burps out of it when it first boots up, the quiets down after about 30-45 seconds.
sound test yields no change in static. I'm not getting and errors or anything on the display.
rusolinio:
check this guide out. Its considered the bible in my home these days.
http://www.pinrepair.com/wpc/index3.htm
lilshawn:
--- Quote ---Insert Quote
check this guide out. Its considered the bible in my home these days.
http://www.pinrepair.com/wpc/index3.htm
--- End quote ---
yyyep...done it all, i'm thinking it may just be easier to source a new one on the ebais and be done with it...it's too old to put on location so someone can buy it and put it in their basement.
lilshawn:
still trying to get this unit operational. the volume chip is good and the amp has been replaced.
does anybody know where or what generates the diagnostic "bong" noise? i believe it's a chip generating the sound (not ROM based) but i'm getting nothing.
lilshawn:
would anybody believe me if i said i have sourced and replaced nearly every chip on the board and the * :angry: word describing sexual relations :angry:* thing STILL doesn't work. replaced all but 4 chips now. 8 mhz and 3.57 mhz clock signals I believe are good. on the oscilloscope it's there, it's timed properly, and at a proper voltage level, the 3.57 mhz just a little ugly. i think it's just a result of the weird high low inverter (3 of them?!) it goes through, i'm going to replace the resistors and small caps in the 3.57 mhz circuit to be sure.
fed the amp an audio signal directly and it plays (amplifies) fine.
:soapbox:
starting to get a little frustrated with this board. :angry:
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