NAD 7100X Repair [Archive] - Audio & Video Forums


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03-20-2004, 12:40 PM
I recently purchased a used NAD 7100X Monitor-series receiver. It appears to have a typical malady that afflicts this model, i.e. intermittent speaker relay operation. As an electronics tech, I have troubleshot the problem, and it is certainly the relays as you can toggle the Speaker A and Speaker B selection push-button and the intermittent failure does occur.

Additionally, I have noted one electrolytic filter capacitor (10,000 uf @ 80VDC) in one of the power supplies (NAD typically has two separate low-voltage supplies) is leaking. Thus, it too should be replaced. In fact, it's probably a good idea to replace all filter caps.

One poster in the "Reviews" section mentioned on his 7400X that he had a similar problem but was able to "fix" the problem with the relays. These relays are sealed, and it's been my professional experience even if you can get to the contacts, cleaning them only delays replacement of the relay.

Does anyone on this Forum have any technical experience with the NAD 7100X? If so, I would certainly appreciate your input, or at least a source for parts. I could just box it up and send it to United Radio in Syracuse, NY, but since I know where the problems appear to be, it would certainly be cheaper for me to repair it.


03-21-2004, 06:34 AM
Within the last few months, I have had two appliances fail due to defective miniature sealed relays soldered on printed circuit boards, probably by the same manufacturer. In one failure, the controls of a GE electric wall oven failed and the oven wouldn't operate because the control board power relay which wasn't even necessary and omitted from the replacement board failed. GE sent several incorrect replacement boards and when the GE technician finally came out to install the new board that turned out to be the correct replacement, he had to call his office for technical backup because of diffenences in the configuraton and connections to the replacement. That took nearly a month and cost $250. Needless to say, with a 3 1/2 year old oven, it was not covered by warranty.

In another recent failure, a 27" Sony TV set has failed due to a failure of a similar relay in the power supply. Since the set is now 18 years old, I'm thinking of junking it although of 3 indentical sets, I have one still in perfect operating condition so I might just save it for spare parts for a while. Still it seems hard to part with a perfectly good televison set for one stinkin $2 relay.

I'd say the best thing to do is replace the relay if it is defective. I know repairing this kind of equipment is a pain in the butt but at least reparing a receiver is a lot easier than repairing this big televsion set. As for the oven, had I repaired it myself and my house ever burned down, my insurance never would have covered it so I left it to GE and ate the cost (raw of course, after all the oven wasn't working.)