Whilst doing some testing for Guddler over on the UK-VAC forum I thought it would be a good time to look into why I sometimes get a POD timeout error.
Normally when I get this error pushing down on the black cable that connects it to the 9010 fixes it.
Here is the reason why
One of the crimps had worked its way loose.
I carefully bent the small bard out a little and refitted. Now the POD seems to be rock solid.
muddymusic dumped the Hard Drvin GAL16V8’s from his board set. They were unlocked so are assumed working but have not been tested.
Thanks to muddymusic
Today I dumped the only PAL from an original Super Pang PCB.Equations are the same of the ‘CW-P’ dump already in the database but device (a PAL16L8) is marked ‘POKER’ on mine board like the PAL from Pang dumped by me some time ago.Equations are the same of the Block Block PAL as well.Dump is tested as working in a GAL16V8 replacement.
My friend Luca sent me this original Konami The Main Event PCB (a decent wrestling game):
After booted up game showed a clear sprite issue:
In these Konami boards sprites DATA are stored in 40 PIN 4Mbit MASK ROM so I went with my logic probe on the two ones @K4 and @H4 and found that the one ‘799B05’ @K4 has some DATA lines inactive.This was confirmed also by the MASK ROM test:
Reprogrammed the DATA into a 27C400 EPROM replacement gave me correct sprites:
Next issue to troubleshoot was the absolute lack of sound.Using my HP10529A logic comparator I found a 74LS74 @G5 with bad outputs but this was not enough to restore sound.Probing the audio Z80 CPU I found that all the control lines were silent so this convinced me to replace it (I had confirm it was really bad as I tried it in another board).At this point I had sound but only some speech samples randomly played.Analyzed the 2018 SRAM @F5 and found weird activity on DATA/ADDRESS lines.Desoldered and tested it confirmed it as bad:
Sound was finally fully restored.Last issue I had to solve was that some Player 1 inputs were not working, for example COIN 1 were stuck LOW as shown in TEST MODE:
As show in schematics inputs are handled by some 74LS253:
Probing the one @E12 with a logic comparator gave me problem on the two outputs, this was confirmed by out-of-circuit testing:
After replacing it TEST mode reported all the inputs working again:
So the board was 100% fixed.
Got this original Super Pang PCB from my friend ‘Mikidaffy1983’
He asked me to desuicide it (picture above is actually from the board already desuicided) and, as usual, I followed instruction here:
https://www.arcadecollecting.com/dead/pre-cps.html
All went good but when I tried the board I noticed wrong colors on some backgrounds/sprites:
Studying a bit the hardware I found that the color RAMs are located @8C and @9C (two 6116) so I started to analyze them with my logic probe, this revealed that some data lines of 6116 @8C were inactive.Desoldered and tested it out-of-circuit confirmed it was bad:
Fitted a good 6116 RAM brought colors to normal.
