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New member Username: John_aPost Number: 81 Registered: 12-2003 | My NAD T760 receiver developed a hum on surround and digital modes. The model is from 2000, and the precursor of the T752. I tried everything I could think of with cables and connections, and made a thread here on that. No joy. NAD web services referred me to my area distributor, and they referred me to technical services at their HQ. A really helpful guy at technical services recommended taking it to my local dealer who would send it to them for repair. I said there were stories on this forum of long waiting times from that chain of dealers, and I would like to fix it myself, if possible. I've trusted local service agents for other brands, and regretted it. So he made some suggestions about the source of the hum, and passed me to the parts department to buy a service manual, which I did. They sent the manual promptly, by post. I located the first component the guy suggested, an electrolytic capacitor on the AC3/DTS board, and replaced it. A bit better, but still bad hum. The technical guy then suggested the old capacitor had probably failed and taken out a bridge rectifier diode next to it. I replaced that. No hum. The receiver sounds good as new. I mention this because the service was excellent, and well informed. Apparently this is a know issue with T760s: the capacitors on that board are rated to 80 C, that one stands right next to a heat sink, and subsequent models had it rated to 110 C, instead, to prevent the problem. My receiver now has a 110 C replacement, and a new bridge rectifier. Cost in money, peanuts. Cost in time, some hours fiddling around. Benefit, receiver better than new, I doubt the problem will recur. Also a great feeling of having learned something, and fixed it myself. Just like "Zen and the Art of Motorcycle Maintenance", if anyone remembers a cult book of years ago. I had never undertaken a repair like this before. Moral. NAD stuff is high-tech and high-quality, but user-servicing is still possible. There is not much you can't do in there with a screwdriver and a soldering iron. I recommend taking off the covers just to have a look round (when it is switched off and disconnected, or course). The build quality is outstanding. This should not deter "set it and leave it" customers. But it is good to know that this standard of service and technical expertise is still found in some places. Mine may be a special case because the distributor and tech centre, AudioNord (Denmark), used to own NAD, before selling it to Lenbrook (Canada). Talking on the phone, I learned some interesting background stuff about the brand from the guy, too. I shall stick with NAD. Apart from the sound and performance, this is how consumer electronics should be. |