Konami Simpsons pcb - player one fire button does not work

KeeperUSA

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Konami Simpsons pcb - player one fire button does not work

Hi all,
A very strange problem. Just bought a Simpsons pcb, and the player one fire button does not work. As a result, can't get into the test options to test the I/O. Player one jump, and player two buttons work.

Testing it on three different jamma cabinets, and same problem. Any ideas? Thanks!
 
I looked at the schematics, P1 shoot/fire button goes from CN1 to S36 to U16. How do you test/diagnose the problem?
 
The problem is either the custom resistor array '005273' @S36 or the 74LS253 @U16.From my experience the latter fails more often.Try first to piggyback a good chip on it and see if this fixes the issue.Or, if you want, go straight and replace it.
 
Yes, as Caius said. It's most likely the LS253. I would socket it when replacing it, as those buffer chips often go bad, so if it ever does again, the next guy won't need to desolder the old one (saving wear on the board).

But in case that doesn't do it, the 005273 can be found at Andy's. Note there are two sizes, so you'll need to measure yours:

http://andysarcade.net/store2/elect...ogame-asics/konami/konami-005273-10x25mm.html

http://www.andysarcade.net/store2/e...ame-asics/konami/konami-005273-8mm-matte.html


But again, it's most likely the LS253.
 
I also have those customs, but not listed on my site.
 
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