Gaborone
Quoted from Ghostcri:Hi all, have a lingering switch/opto issues with my BSD.
I've been trying to get this BSD fully working for awhile and am stumped. My issue is that switch 77 (R Ramp Up) when pressed, triggers ALL of column 5. Switch 77 is a physical switch where 7 of 8 of the switches on column 5 are optos. I have replaced the switch and its diode and have tested the actual switch in other areas of the machine and it only triggers once when connected to other switch wiring in the game. The machine has a new MPU as well as a new 10 opto board. I verified that J207 on the MPU is wired and connected correctly. J207 is clean with no previous acid damage. I've tested all of column 5 and each opto and switch triggers properly in test mode. Not sure where to go from here...
I appreciate any help!
First - there is NO acid - ZERO, it's battery damage which is alkaline, the EXACT opposite of acid!
Now that we have that cleared up, it isn't around J207 that you need to be looking, it's around U20 and the 4 x LM339's to the left and right of it - basically the entire area UNDER the battery holder. BUT, as you say you have a new MPU PCB that probably discounts that idea.
REMOVED: Study that area very closely or put CLEAR, CLEAN closeup pics on here for inspection.
What happens if you leave that switch disconnected and play a game?
Cincinnati, OH
