Nad c-370: Right Channel drops out

I took my NAD to a local repair shop to investigate why the right channel goes out on my amp and they proposed to charge me $420 to install a main amp kit, a filter set plus labor. Needless to say, I paid them their $70 "diagnostic fee" and brought the Nad home, unrepaired.

I am a bit baffled because I can get the right channel to come on if I tinker around with the amp by switching source inputs form CD to Video and so on. I have been reading on the internet about problems with these amps due to capacitors overheating and bugging out. Is there a particular capacitors or group of capacitors that I could replace myslef and get my rig running again?
If you contact NAD they will refer you to an authorized repair center and they should charge around $50 for the estimate. (You would have to pay shipping though.) I wouldn't mess w/it unless you really know what you are doing. Have you tried cleaning the balance, volumn and input switches? Also, it may be a loose solder joint. Good Luck!
What's a 'main amp kit'???
I dunno what a "main amp kit" is...that's what they told my girlfriend is needed (plus a filter set.) I did not get to talk to the technician. The only one I got to talk to was the lady at the front desk who held me up for $70.
what would I use to clean volume, balance and input switches besides compressed air Magfan?
Well, Tbone, I don't know.
RadioShackup has some stuff. Read the label, then the same label at the 'audiophile' shop which will be 5x the cost and probably the same stuff from the same pipe.
Use per directions. I HAVE NEVER USED THIS STUFF, so I don't know any potential downside.
REPEAT:: I have never used this stuff, so read the can. TWICE.

Also, I know it isn't fair, but women STATISTICALLY pay more for cars than men, even comparing identical cars / equipment. So, when they see a woman come in to pick up some electronics, they feel free to BS away, even if it is another woman behind the counter.....Isn't sisterhood powerful?

I don't know current (no pun intended) practice, but large caps come with screw on contacts. These are easily replaced, if they are connector up. Sometimes there is a band around the bottom, sort of like a hose clamp, to keep the caps mechanically secure. After everything has been unplugged for a couple hours, it should be OK to service. WARNING.....WARNING:: Caps typically come with some 'bleed' resistance across them, so they won't hold a charge for long. If these resistor(s) are defective a cap can hold a LETHAL charge for quite a while.
If you aren't comfortable with this procedure, have a REAL tech do it for you.

If you believe in 'audiophile' caps, you can either specify at time of work order, or bring 'em in yourself. Cap size can vary, even for same rating, so be careful there, too.

Now that I've either A) scared you or B) confused you, please feel free to follow Kotta's advice. Probably better than mine!
Seldom is it cost effective to repair any electronic unit where the original, new cost was less then $1K. Typically any repair will cost $180 plus. and that is just for the estimate and shipping cost. Think about it, a used, in perfect operating condition unit that cost $1K, is worth no more then $480, tops. Better to buy a new unit, with a three year manufacturer warranty, and sell off the old one for parts. Repair of electronics in the $1K or less original cost is an oxymoron.
I ordered a musical fidelity a5.5 amp as soon as I got the news on the NAD. Remarkable improvement in sound stage over the NAD plus I can hear details that I never noticed with the NAD. I am pretty happy with the step up but now I need new speakers to replace my old Klipsch KG-4's. Harbeth and Spendors look appealing. Anyone have any recs on speakers to pair with my new amp and arcam cd23t CD player? I like the look of a more traditional box type speaker rather than towers or some of the oddball looking stuff that is favored by many. My room is about 15' x 20' with carpet and a 10 foot ceiling. Rock and Roll and bluegrass are my main choices in music. I like to feel the bass as well as hear it.

Is a busted NAD worth anything?
Put the busted NAD on ebay with disclosure.
At least you didn't pay $420 for something unknown.Even if you gave them the $420,you still might have an amp that needs new caps.There are a lot of shops out there looking for easy money.That makes it harder for the true good shops.
I don't think the shop even took the cover off. If they did, they didn't seem to make any attempt to blow out any of the dust inside of it.
Maybe a shop/dealer that's been around for a long time selling upper end gear.If they don't work on your brand,they might have a good shop to go to.A dealer in my area that could be trusted with anything retired.Nobody bought his business most likely because he was mainly a stereo guy.With the new tv's,everybody wants multichannel home theater. Last resort I guess like suggested above, shipping out might be the best option.Packing,shipping, bummer.
I know there is sometimes special knowledge involved, but really. Once a tech has the schematic and test values what could possibly go wrong? Mechanical disassembly except in special cases is pretty routine.
The only 'glitch' in the ointment would be proprietary parts / devices or, for example, the 'potted' gain cell circuitry in my PS Audio integrated. I don't see NAD using any such parts or devices.

Any tech should be able to fix a NAD amplifier unless a board has been charcoaled.
10-11-09: Magfan
I know there is sometimes special knowledge involved, but really. Once a tech has the schematic and test values what could possibly go wrong?
Well that truly made me lol. Magfan, I'm guessing you aren't a technician.
Well, as a matter of fact, I've worked on semiconductor processing equipment for decades. I was expected to be able to fix darn near anything, at least to the board exchange level with schematic, knowledge of how it was supposed to work a meter and scope.
What's the big deal? It's just an amplifier.
I know I simplified things, but after all, if you are dealing with a professional analogue tech who is familiar with amps, preamps and can align an FM tuner or use a tube tester (for vets only) I don't really see the problem.
Is how this stuff works a mystery? Do you need to be admitted to some cults inner circle? Is fixing stuff Masonic or Religious?
Nope, it's just electronics.
Sound technique and reasoning will get you thru many fixes with no special knowledge. Maybe not even a third, but you can really fix stuff without resort to dead chickens or tea leaves.

Back to the OP. See where he writes::
'I can get the right channel to come on if I tinker around with the amp by switching source inputs form CD to Video and so on.'
I don't know? Cold Soldier? Bad Switch? Bad Switch logic if it's logic or relay driven switches?
Point is, this is not voodoo or rocket science. It all works the same way. Same principles, same parts (mostly not proprietary) and a volts a volt.

Granted, some techs are better than others. I, personally, was only OK at semiconductor equipments electronics but very good at mechanics and troubleshooting / reasoning. A good tech is certainly worth knowing and cultivating. It's a gift.
Magfan, your second paragraph had me chuckling again. I'm not arguing the logic you put forth, it is a rosy picture though.
Agree 100% with your closing sentence. I have known a few truly gifted techs.
I think the main thing is to shop techs. The OP was not served by the original guy who saw $$. In all my years of fixing stuff and as a process technician in a place making integrated circuits and discreet, the #1 thing I learned was to get a good description of the problem and what happened.
Asking the right questions are critical.
People don't realize they are setting themselves up with stuff like 'It's broken'. The more info a tech has, usually the better.

Is the NAD still available for inspection? I'd sure like to see it and try some contact cleaner. Worst case is you're no worse off than you are right now......

When I brought my old Carver Cube (M400t) to the tech, I was able to give a pretty good description of what / when / where and the POWER GLITCH that took it out. The electric company bought that fix for me, since I kept good records and knew exactly when my amp went south. What a Chinese puzzle box it is. It worked another 5 or 6 years after the fix, so I guess I got my $$$'s worth.

I've never worked hi-fi but this amp doesn't sound too broken for a little experiment. You may get lucky and fix it. Contact cleaner, anyone?

My preamp for the Cube was a Kenwood integrated amp that I cracked the case on, and found (sheer luck) that the main board and preamp board were strung together with jumpers. snip snip / solder and I had a preamp which lasted until I could afford a real preamp.

Rosy picture? Sure! My pleasure! No harm in trying something rather than getting a 400$+ bill for a repair. Always ask for the parts back, too. Sometimes my rants make me laugh, too.
thanks Mag fan. I'll try blowing it out with a can of compressed air and then follow up with the contact cleaner. It looks a bit furry inside. I have have dogs and cats and unlike most audiogoners who post items for sale, I smoke like a freaking chimney!
Some audiophiles do an annual cleaning. Others will pull / clean connections and use contact stuff on 'em. I try to keep my gear is a dust resistant area, while still keeping warm running stuff cool.

Smoking and pets are deal breakers, for sure. Cats are the worlds only source for real cat hair.

Are the switches mechanical or electro/logic? I guess I gotta look up a picture of this amp!
I am not sure what type of switches the amp has. I will try the cleaning this weekend and see what happens.

Surely more audiogoners have pets and smoke than what the for sale adds would leave you to believe...
It's notable to me that (much like British cars)for all its positive qualities NAD simply isn't reliable as a brand--these forums are full of NAD gripes and problems. Thinking back, I've owned five or six NAD pieces (amps and sources); all but one had issues. Correspondingly, comparably positioned gear from rivals like Rotel and Integra seems indestrutible.
My 1 bit of NAD ownership was troublefree for 2 decades. The piece? An old 1700 tuner/preamp.
It worked without complaint, even the remote, until the day I gave it to charity.
Prospective buyers wanted it for the phono section which I broke by doing a quick disconnect (ZAPP!)
But that was not NAD's fault. Mine entirely.

Did NAD's quality take a hit when they went Chinese? / Asian? Where were they constructed in the 70's / 80's / 90's???
After cleaning:

Try plugging the CD player into another input.

Check the jumpers just in case and if you are using the level controlled pre outs on the back, try the fixed ones instead.

Consider using a sheltered equipment rack and some routine cleaning maintenance to keep out the smoke and pet hair.