I really couldn’t find much info on this but what chip on the MPU would control row 5 on the switch matrix on a system 11b? I have a goofy short (flickers for 3 seconds, then nothing for a small period of time then triggers everything on the row for a couple of seconds) and want to get my WW up and running ASAP! Thank you for any help!
Have you checked all the switch diodes on that row?
I’d be checking every switch as the first step - a broken/faulty/poorly soldered diode will totally screw up the matrix.
rd
Quoted from rotordave:Have you checked all the switch diodes on that row?
I’d be checking every switch as the first step - a broken/faulty/poorly soldered diode will totally screw up the matrix.
rd
I moved this board from a BK2K that was showing the same issue.
I put the original WW board in the BK And it’s working fine
Switch matrix strobe drive is U38 PIA to U40 LS244, row return is U30/U39 to U38 PIA.
Hopefully it's one of the 4011's u39 which looks to be the row in question from the crappy PDF schematic I'm looking at.
Do you have schematics for your game you can look at 'switch matrix input' on the mpu board page and maybe see the signal better.
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Middletown, OH