NAD 390DD Troubleshooting


2015-04-04 12:56 am
One day my NAD 390DD stopped powering on. It has the same system as a fellow poster here, so I tried the suggest repair without doing much diagnostic work. Afterwards, the symptom is still the same: apply power, orange standby LED comes on at the ON button. After pressing the ON button, then LED turns blue, and a single relay click is heard, but the VFD does not come on.

I didn't notice a bulge in any of the electrolytic capacitors.

There is about 2.5V at the ACDETA and PSUFA points. I suspect they should be higher.

The 12.5V measures 12.3V.

Any suggestions on what to measure, or what the ACDETA and PSUFA should measure based on the schematic?


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