SORRY, I missed that sentence.
Remove all power from monitor. Disconnect the collector or transistor x701. Apply Power. Check b+ at the emitter of power regulator transistor x04. if b+ is normal change x701 and d701. If too high change x04,x901,x902 d905 and c905. If still too high and you...
1. check coin switches with meter
2. check that black wire is going to com and the other wire is going to n.o. on coin switch
3. check continuity of wires from switches back to board.
4. possible pia problem
go7 monitors are very old. If you really want your game to last a very long time, replace the monitor. If you want to continue to use the original, purchase a cap kit and replace every cap in the chasis. This is a very good starting point.