Left channel problem in HT system, Woodman, Others?

[IRG]

Hey all,
It's been a while since I've posted much. This problem came to me today from my brother-in-law who currently lives in Brussels, Belgium. Read below for a very good description of the problem. The store where he bought his NAD receiver is no longer in business.

Any thoughts? It seems to me to be a problem swith the receiver, somewhere is the chip set for surround mode. Here is his problem:

"You may recall that my receiver is a NAD T742 and with that I got a set of JMLab Sib speakers (5) and a JMLab Cub sub.

Over the weekend my left front speaker seems to have developed a problem - that is, no sound in most settings (other than the low-pitched hum of being on). When I do a set-up test, all the other speakers produce the standard test sound but the left front speaker (LF) gives nothing.

However, when listening to FM/AM in the stereo setting I got perfect sound from both left and right front. As for other sound configurations while listening to radio, on most occasions LF is either almost non-existent, with crackle, or much quieter than the other settings.

As for watching TV with the receiver set to "Sat" the situation is really weird:
(a) In the "Ears" set-up I get full volume from RF, C, RR, LR but only crackly sound from LF;
(b) In "Stereo" I get sound only from LF!!
(c) And on the other various settings (e.g. Pli Movie, Pli Matrix, ProLogic) I get a combination of working speaker but always with LF being full of crackle and much quieter than the others. And - it may be my imagination - but the more advanced sound configurations seem to be outputting at much lower volume than previously.

Finally, the DVD story is straightforward - all speakers except LF seem to be working normally.

Now, I've checked all the connnections at all speakers and at the rear of the receiver and everything seems fine. What is really strange is that the test programme registers LF as having no output yet while in the "stereo" mode for TV only LF works and in "stereo" for FM/AM both LF and RF work in combination as they should. And for virtually every other option LF is either producing at much less volume (plus with crackle) or not at all.

Do you think this sounds like a speaker problem, or a receiver problem, or both? Neither receiver nor speakers have been hit / spilled / sat upon so I can't figure where this problem comes from.

What would you recommend I do before trying to track down somebody who could take a look at this for me?"

THANKS ALL. irg

[drseid]

I doubt it is a speaker problem because the LF speaker plays fine when using some inputs. My guess is it is a problem with the receiver. Maybe a shot processor?

---Dave

[IRG]

I doubt it is a speaker problem because the LF speaker plays fine when using some inputs. My guess is it is a problem with the receiver. Maybe a shot processor?

---Dave

Yeah, that is my first hunch too. Too weird that it works fine on AM/FM but not with other other kinds of surround application. Any other test he should try? How much is a processor to replace? This receiver is only 1-2 years old. Thanks for your reply. irg

[drseid]

Yeah, that is my first hunch too. Too weird that it works fine on AM/FM but not with other other kinds of surround application. Any other test he should try? How much is a processor to replace? This receiver is only 1-2 years old. Thanks for your reply. irg

I don't claim to be anywhere near an expert in this area, but I believe the processor may account for well over 50% of the price of the receiver. :-( This may especially hold true once you include the cost of labor to fix it.

As receivers and pre/pros drop in value faster than just about any other part of the A/V chain (due to new technologies coming out all the time), it may mean that (gulp) it is a better decision to buy a new one. That said, getting a formal repair quote can't hurt. At worst your friend would be out $30-$40 for a repair guy to crack the receiver open and get an estimate... Maybe it is a lot less to fix than I am thinking (or maybe it is something entirely different wrong, and it is an easy repair?)...

My advice is to bring it to the shop for a formal estimate, and make a "go/no go" decision after hearing what the "damage" will be...

Wish I had more positive advice...

---Dave

[woodman]

It's seldom that I can agree with drseid on much of anything, but in this case I'm gonna chime in with pretty much the same advice. That would be to bail out of this bad boy and replace it with something other than a NAD, like a Yamaha or Onkyo ... or even a Denon or Marantz. Something reliable for starters, plus from a company that actually cares about their customers (something that NAD doesn't appear inclined to do).

This is NOT gonna be a simple, easy, and inexpensive repair. Surround sound processors themselves are NOT expensive ... in fact they've become rather inexpensive. But the labor involved in replacing one CAN be either quite expensive, or in many cases - problematical. Some companies won't even supply such parts by themselves, but instead will insist in an entire new pc board replacement. In that case, the replacement "part" can be as drseid suggests equal to a major part of the cost of the unit itself!

Hope this helps -

[drseid]

It's seldom that I can agree with drseid on much of anything, but in this case I'm gonna chime in with pretty much the same advice.

Backhanded personal attack aside, I am glad to hear we agree on *some* things. :-)

That said, I hope I am wrong on this one, as I hate to see someone have to buy a new receiver after only 1-2 years... I have been there, and it is painful. :-(

Happy listening,

---Dave

[Mania]

A little over a year ago, my reciever did a similar thing. I didn't try the am/fm source, but with every other source, the left speaker crackled and gave very little true sound. I assumed the receiver was toast until someone on this board reminded me of the extended warranty on Sony ES receivers. Since it was under 5 years old, I was able to get Sony to fix it free of charge. However...after I brought it to a local Sony authorized place here in D.C., the guy there said he couldn't replace the processor, and that I had to send it directly to Sony. Although it was a minor pain, it all worked out and I didn't have to pay a dime. But, the reason I'm telling you this, is because even if you take it to get fixed, that shop may not even be able to do the repair. Good luck.

[IRG]

A little over a year ago, my reciever did a similar thing. I didn't try the am/fm source, but with every other source, the left speaker crackled and gave very little true sound. I assumed the receiver was toast until someone on this board reminded me of the extended warranty on Sony ES receivers. Since it was under 5 years old, I was able to get Sony to fix it free of charge. However...after I brought it to a local Sony authorized place here in D.C., the guy there said he couldn't replace the processor, and that I had to send it directly to Sony. Although it was a minor pain, it all worked out and I didn't have to pay a dime. But, the reason I'm telling you this, is because even if you take it to get fixed, that shop may not even be able to do the repair. Good luck.

Thanks Woodman, Mania and drseid, my advice to my brother-in-law was exactly what Woodman mentioned- get a Yamaha or Onkyo (or Denon, Marantz). My trusty Onkyo 575x is about 6 years old and is used by 5 year old, and is on all day long, and has never missed a beat. I like NAD stuff, I just don't think their reliability is what it should be.

I will have to check the warranty issue, but I think it is past, and the shop that sold it went belly up. My other advice to him was to take it to a shop that has a repair technician, and a shop that also sells Yamaha or Onkyo, and if the NAD unit is beyond repair, or too expensive, make a deal to buy a new one from them if the diagnosis is free. Sound like a plausible idea? Thanks again.