NAD 7100 Receiver: No sound from left Speaker/ Headphone out


2010-09-18 4:31 pm

I got a NAD 7100 receiver for repair. I dont get sound from the left speaker (it doesn't matter speaker group A or B). I don't have sound on the left channel when I plug in headphones too. Balance and volume rocker seems to be OK.
I did also checked the "braze point (?)"... But they seems to be ok (I don't have bad contact when I tap with the rear from a screwdriver over the circuit board).
What I did see: When I tap with one finger the bridge between "pre and main amp" from the left channel, I can hear a buzzing noise from left speaker/left headphone channel. When I tap the bridge from the right channel are there no buzzing noises...

Anyone any ideas what that could be?

Many thank from Switzerland (excuse my english - I'm still learning)...
You do not indicate how HARD you are hitting the Bridge Rectifiers ??

I would resolder the connections to the board where the transformer, bridge rectifiers, any fuses and PSU capacitors are mounted. Then test to see if you have DC voltage across the PSU cap's. As one channel is working, you can use this to compare any voltages that you measure.