Downtown Doug Brown
a day ago
- The author attempted to power on a Macintosh Performa 450 after a year but it failed with the startup sound followed by the 'Chimes of Death'.
- Using Apple's Serial Test Manager via a serial connection, the author diagnosed the issue as a RAM Bank A failure, specifically bit 11.
- The problem was traced to a broken trace caused by residual capacitor leakage, and a bodge wire was used to bypass the damaged connection.
- The author successfully repaired the machine and noted that the same diagnostic tool had helped fix another Performa model earlier.
- The process can be replicated in an emulator using MAME with a custom patch to simulate the RAM fault.