NAD T751 left channel dead

[mips]

Hi,

I noticed today that there is no sound output from the left channel of my nad t751 a/v receiver. Only thing you hear occasionally is a scratchy/crackling sound almost like when trying to manually tune a fm radio.

Where do I even start to try and identify what lost it's magic smoke so I can try and repair it? Still need to go hunt for schematics as well.

Thanks in advance.

[madan1]

Re: NAD T751 left channel dead

Is this happening on all audio inputs ( radio, cd, 5ch in, aux, etc. )?
See if there is audio signal on the left channel pre-out rca connector and on the headphones.

[mips]

Re: NAD T751 left channel dead

Is this happening on all audio inputs ( radio, cd, 5ch in, aux, etc. )?
See if there is audio signal on the left channel pre-out rca connector and on the headphones.

Yes all inputs.

I'll have to check the pre-out, dunno how to check the headphone jack.

[madan1]

Re: NAD T751 left channel dead

plug in headphones

[mips]

Re: NAD T751 left channel dead

plug in headphones

I don't have any

[CapLeaker]

Re: NAD T751 left channel dead

Can we have some pictures to see? Here is the Service Manual for it.

[mips]

Re: NAD T751 left channel dead

Can we have some pictures to see? Here is the Service Manual for it.

Thanks for the service manual.

What would you like pics of and I'll take some?

Thanks

[madan1]

Re: NAD T751 left channel dead

Did you check the headphone output and the pre-out outputs?
What about the surr outputs - are they working?
What about digital audio signal?

If the problem is affecting only 1 channel and the unit is powering up, my guess is that at least the power amp section is OK. Now you will have to find where the signal is lost. It could be faulty relay, bad board connection, bad op-amp, etc.
Do the above test to narrow down the options.

[mips]

Re: NAD T751 left channel dead

Ok I have not done much about this but the weird thing is not so long ago both channels started working again and then back to left only. Today the left channel is dead but the right channel now works, wtf!?!?

I dunno if it's my imagination but the relay no longer sounds the same when it kicks in, it use to have a lot louder click from what I recall.