I'm trying to get an Apple II+ clone fully working (it boots up like it should, but there's no response from the keyboard -something I'm looking into, suspecting the keyboard itself needing repair). However, there are some other things worth considering like the power supply output. With the computer switched on I measure these voltages:
- 12.009 V
+ 11.480 V
+ 4.998 V
- 5.033 V
My concern is the +12V line. Is it too low? if it is, what action will likely remedy this?
Another thing: there's a 0.5pf trimmer capacitor near the 14.31818 MHz crystal oscillator (bottom left hand side of the motherboard) -what's it for? The two other trimmers on the board are for adjusting the video output level and color trim, but I have no idea what this one is for.