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[sdiy] System 100 101 power supply issues

2026-02-17 by Todd Sines

Finally, getting around to getting this thing fixed.

#1: power supply. No +/-15V voltage.

Recapped the entire supply, no voltage.

Then I tried to replace the Roland 022-86C (100-120V) transformer with a Triad Magnetics toroidal transformer that delivers +/-15V, still nothing. Wondering if anyone else here has done work on one and what the typical points of failure were my were, perhaps the L723DC / LM723CN?? Or the 2SD-324 voltage regulators? Nothing is burnt out, and I’ve definitely got the winding correct.

Got any other ideas? Thanks,


Todd


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