Next job was to repair the sound board which wasn't working. after some searching with a logic probe i found the main tone oscillator IC for the scoring tones was only outputting one tone instead of three. so i replaced the IC (LM324 which i didnt have so i substituted a TL064). i replaced the ceramic caps as well for good measure. When it still wasnt quite right (one score tone still not working), and after some more tracing i replaced U8 and U9 as well which fixed the board.
Next i had to repair one display which was out, which turned out to be a faulty 4543 decoder IC.
All this had the game pretty much up and running
i still have to remove the drycell battery pack from the MPU and remote mount it (the batteries were soldered to the board)! but i need to buy a battery holder so that can wait until i can get a chance to get one.
