I was able to track down the issue for my last problem and now have my +15V, -15V, and +5V rails. ๐
However, I still have problems with the unit and suspect the CPU. Current problems include a constantly spinning turntable, no response to keyboard input, and a display that goes between showing one dot and multiple dots. I’ve confirmed the keyboard presses do take the appropriate pins low.
Here are my readings; does all look okay from the CPU side of things?
PIN # 1, 5V, DATA LINK
PIN # 2, 5V, KB: PLAY
PIN # 3, 5V, KB: STOP
PIN # 4, 5V, KB: DOWN
PIN # 5, 5V, KB: UP
PIN # 6, 5V, KB: 45
PIN # 7, 5V, KB: 33
PIN # 8, 5V, KB: PAUSE
PIN # 9, 4V, DATA LINK
PIN # 10, 2V, CRYSTAL
PIN # 11, 2.3V, CRYSTAL
PIN # 12, 0V, GROUND
PIN # 13, 5V, DIGIT SELECT OUT
PIN # 14, 5V, DIGIT SELECT OUT
PIN # 15, 0V, DIGIT SELECT OUT
PIN # 16, 5V, DIGIT SELECT OUT
PIN # 17, 5V, BCD OUT
PIN # 18, 5V, BCD OUT
PIN # 19, 5V, BCD OUT
PIN # 20, 5V, BCD OUT
PIN # 21, 5V, ?
PIN # 22, 3.5V, INDICATOR
PIN # 23, 5V, KB: TURN
PIN # 24, 2.5V, LIFT
PIN # 25, 5V, <<
PIN # 26, 5V, >>
PIN # 27, 5V, SLOW <<
PIN # 28, 3V, SLIDE TACHO
PIN # 29, 3V, SLIDE TACHO
PIN # 30, 5V, 5V
PIN # 31, 0V, LIFT MANUAL
PIN # 32, 0V, SO
PIN # 33, 5V, DISC DETECTOR
PIN # 34, 5V, SLOW DOWN
PIN # 35, 5V, FAST UP
PIN # 36, 0V, SLOW UP
PIN # 37, 5V, FAST DOWN
PIN # 38, 2.5V, POWER ON/OFF
PIN # 39, 4.5V, RESET
PIN # 40, 0V, SPEED SENSOR
Note that PIN 38 is sitting at 2.5V (is that correct?); I thought it should be either 0V or 5V.
The same comment goes for a few other pins. I thought it would be either low (0V) or high (5V).
