Response from Jonathan: Tim,

Just from what the owner told you, I can probably guess that he doesn’t know too much about repairing arcade games. Sounds more like your problem is related to a board issue. It could be a power supply issue but that’s actually less likely in this particular case. With that said, probably still a good idea to start by checking the power supply to make sure the correct voltage is getting to your board. After you check that, you might check out this page which has pictures of Donkey Kong symptoms and how to fix them. If you don’t exactly see your problem in these screenshots, you might try using the chip table to identify where the problem is.

I know you said it was inconvenient to take a picture of the screen but that would really help us troubleshoot your issue. If you still need help after you’ve tried these steps, try to shoot us over a picture when you can. Thank you for your question and good luck with your repair.