So, I recently got a Commodore 64 from one of my neighbors along with a 1541 disk drive, Commodore 1701 monitor, and I found a psu for it at a local vintage video game store. I tested the psu and the 9v and the 5v lines are working. So, I plugged it in the Commodore 64 and turned it on. The LED did not turn on and the screen was a solid black color. I took a look inside and everything looked visually okay. So, next I poked around with my multimeter and found only 1 volt on the cassette port. I know the 5 volt line makes it to the board because I measured the voltage on the power switch and the input and output voltages were 5 volts. So, I let it sit for about 3-4 minutes and then checked the voltage again. For some reason, the on board voltage was at a healthy 5 volts, but the screen remained a solid black color. I don't know what to do at this point. Could it be a bad capacitor, chip, voltage regulator, or something else?
Board Revision: B
Using RF output for the display
Z key missing