Hello - excited to finally got my Thief project to come to life after adjusting down the B+ and had a couple questions:
1) PCB - I get only green when the game boots (see pics). The game seems to boot inconsistently, though Power Supply voltages seem solid (around +5.1v, -5v, -12.3v). I'm sure the monitor needs a cap kit, but thinking I have board issues as the G07 displayed a blue screen at one point when the game wasn't booting. At one point I was getting a droning "wa, wa, wa" sound, which didn't sound normal. Upon inspection I noticed I'm missing a chip at A13. According to the schematic, it looks like A13 partly controls red/blue, so hoping that's my answer. It looks like a stock chip, but the hand drawn text is a pain read - is this 74LS189?
2) Tape Deck - seems to send loud signal through the speakers despite the volume, but nothing that sounds like police banter. I know there's a great digital solution out there that I may end up doing, but want to at least attempt to fix this thing since the tape deck adds a coolness factor to this game. Is it realistic to attempt a repair or are these players a lost cause? I realize my tape could also be roasted, but haven't been able to confirm yet.