Hey all.
So I have been working on a beat up Demolition man for the past couple of months and I am having one last (or so I hope) problem that is really stumping me. At first the lower ball release and right jet bumper coils were locked on as soon as the game was powered on while the diverter hold and top popper solenoids would not fire at all. I replaced the Tip36c, tip102 and predrivers for the high power coil and the tip102 and pre drivers for the low power coils. Turned it back on and nothing changed. Anyhow replaced the u4 and u5 ls chips upstream and BAM no more locked on coils but still no working top popper or diverter hold. I have desoldered and checked all of the diodes and resistors for both of these and all test good. When I test the top popper transistor tip 102 to ground it fires and the u5 and u4 chips I replaced earlier should indeed be the ones controlling everything. Is there somewhere else I should be looking?? 20 pin connector?etc? I am really stumped here. Thanks for any info.