I have fetched a Comet that apparently had not played for ages.
When switching on the machine here are the symptoms.
- playfield GI or part of the GI works
- MPU boots properly with a digit code 0
- no display working
- no sound except hum
- no reaction of the coin door button, start button, nor adding credits from the door
- Surprisingly, at machine switch on: flipper bats, switches and coils are active. If I press flipper button or I press the sling rubber coils work. And I have not started a play !!! I cannot say much more as I see nothing on the screen and there is no reaction from the diagnostic buttons.
- I have the 12vdc and 5vdc on the Power Supply board.
Also as you can see on the pic, someone in it life has added a wooden board with a PCB, and button, at about 10" from the coin door.
Anyone can help me to dig further into that ?