My first post. I guess I've been lucky so far and able to fix my issues in the past, but this one has me confused.
To start, I did have some very light alkaline leakage. I brushed off the bloom and played a few games with no issues. I thought I’d neutralize any remaining alkaline so I pulled the board and dabbed on some vinegar solution. Reinstalled and got a ton of problems. Ground short row 1 stuck closed, Row 1, 3, 4, 6 and 7 errors, clock broken and ball popper stuck. Flash lamps behind the gumball, in the right corner and next to the slot entrance are now stuck on. Random coils firing, etc.
Seemed like the CPU board was toast so I replaced 74LS374 with no change. I punted and bought a new Rottendog CPU board… No change. Grrr.
I could find no wiring issues under the playfield. The clock HAD been working well (PinLizard board from maybe 15 years ago). I unplugged it and it cleared up many of the issues. With the clock unplugged and all flash lamp and coil plugs removed from the power driver board, I now get one error: Clock Broken.
So the issues now:
• I tried to start with the coil and lamp plugs installed on the power driver board and it instantly blew the 8 amp fuse before the transformer. (I pulled them back off)
• Left magnet and gumball entry optos not working in switch test
• Power Driver TP 8 reads 36 V, fluctuating to 7 (should be 18 v)
• Clock broken (disconnected)
• DMD is scrambled on initial start-up but works fine after (Didn’t used to do that)
Not sure what to try next. My first thought was the custom 10 opto is blown and to replace the LM339 chips. And / or to replace the 2 opto pairs that aren’t working. Looks like also the 18 v circuit needs help (BR1 and associated components).
I guess my main concern is what did I do to cause so much carnage, and am I causing more issues trying to diagnose things? Thankful for any ideas.