NAD AV 713 right channel bad

[hostarn]

Greetings,

Its been a while for me on this forum. But when I found myself in this tight spot with my amp, I knew where to go for help. Always impressed with you guys on this forum I will once again beg for advice.

Here goes. My NAD AV 713 right channel is extremely low, only by listening extremely close to the speaker I can hear that there is some sound. The probleme is the same if I switch from A to B speaker output, aswell as the headphone output. My instinct says perhaps a capacitor on the right channel. a quick look inside shows no visible bursts or burns. Fuses OK.

So, anybody out there with experiences similaire to mine? With an idea perhaps?

Anyways, thank you in advance for ideas and tips.

Regards,

Eric

 

[hostarn]

There are two small black boxes behind the speaker outputs, what are those? Relays? It's been awhile since I did this.

 

[hostarn]

Well its not the relay, nor is it the big cap on that channel. I hope its not a transistor. I get a really low signal.

 

[JonSnell Electronic]

I cannot find a schematic for a NAD AV713 is it a 714?

 

[hostarn]

I cant find it either. It might be a similair soundstage but the AV 713 is a 5.1 receiver. anywho, symptoms are left channel good, right channel extremely low. Relays and big capacitors are checked and in the clear, aswell as the fuses.

 

[JonSnell Electronic]

Reset the uController. There should be a reset sequence, that may cure the problem. It sounds like a uProcessor issue, quite common in high end Denon and Yamaha.

 

[hostarn]

I have never heard of such a thing. Whaa? What is it? Where is it? How do I go about resetting it?

 

[hostarn]

Are you talking about a chip?

 

[JonSnell Electronic]

All microprocessor based systems that process audio/video and indeed computers have a reset routine. If the reset routine is not in your instruction manual I would advise a phone call to NAD or the dealer you purchased it from. As the model number is not traceable, I cannot advise any further. I had a similar problem with a Yamaha DSP. After numerous checks of the power amplifier stage, that was cured by a system reset. A bit like returning your PC to factory settings.

 

[hostarn]

I have now notices a low noise in the right channel ( when nothing is played) while the left is silence.

 

[hostarn]

So DC offset is the same in both channels. I mesure 52 in the left and 55 in the right channel, multimeter set on 200m.

Summing it up.
1. Left channel is good.
2.Right channel is extremely low, with a humming noise (also very very low),
3. Right channel sound and hum does not alter with volume knob
4. Relays are OK and DC offset the same on both channels.
5. The problem is the same on all input channels and switches side if I change speaker cables.
6. The problem is also the same in headphones.
7. No scratching or anything that would indicate a pot problem.
8. Fuses OK.

Man alive, getting frustraded.