Macintosh 512K ED (JG 7)
This computer belongs to a customer. When I received it, it wouldn't power on at all.
Work done
- Inspect the boards
- Replace bad capacitors
- Diagnose and resolve power issue
- Service floppy drive
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Analog board
There were two RIFA paper capacitors installed on the logic board, these tend to go bad and explode, so they had to be replaced first.
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After that I could go ahead and start working on the power issue. While testing the resistors on the primary side I found a 33Ohm resistor which went high to several mega ohms. After replacing it, the computer started normally.
Floppy drive
The floppy drive was in good condition, just a bit dirty and the grease had dried up. I disassembled the drive to fully clean and lubricate it:
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