Hi, I own an Olivetti M10 (99% the same electronics of the Tandy (TRS-80) Model 100) that suddenly stopped working and I would like to take this opportunity to know something new from something really OLD
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I was hoping that one of you can suggest me some measurement to perform to track the fail or some other expert around the world to ask to.
The unit is in quite good conditions and was working perfectly until i touched the backup battery switch while the unit was powered.
Actually the backup battery was removed long time ago because was dead but everything was fine without it.
From the schematic i can't really understand why moving that switch can cause any issue and may be was just a coincidence.
Now if i power the unit (with 4 AA battery or with the power adapter) i can hear a tic on the beeper, the LCD turns on but no characters appear (i can adjust the contrast but i can get only dark pixels).
I found online the ROM dump and with a programmer i compared the content that was OK.
I also built a small circuit to test the LCD and it works.
Any suggestions?
Mauro