NAD Monitor Series 3400

From Repair Wiki
Jump to navigation Jump to search

The NAD 3400 was their top of the range integrated amplifier built between 1985 and 1989.

NAD Monitor Series 3400

Problem Solution

Device stuck in stand by

Replace all electrolytic capacitors on the digital control board 72-2284-0-0. The 5.5 V cap is a 47,000 μF (47 mF) supercapacitor.

Speaker relays not working or working intermittently

Resolder and clean switches "Speaker A" and "Speaker B" at front panel, reflow solder joints on speaker relays.

Broken bass/treble potentiometers

These are dual gang 4-pin potentiometers. The 4th pin is a center tap used for better precision. A dual gang center tapped logarithmic potentiometer of the correct value, that fits physically is not easy to find. I managed to find a replacement on Aliexpress.

bass/treble controls not working as intended

clean both frequency selection switches with a lubricating electronics cleaner (I use Tuner 600).

Credit[edit source]

Original article credit: AMelbye