Ando Posted March 7, 2017 Share Posted March 7, 2017 My NAD M3 sometimes switches to stand by mode in the middle of playing music. Sometimes it even switches from stand by to completely off. The amplifier has protection against short circuits and overheating. I have tried changing the speaker wires and also the speakers but problem remains. The problem wouldnt seem to be actual over heating as the amp is only just perceptibly warmer than cold to touch. Sometimes the amp runs for long periods at higher output without going off sometimes only a short time at low volume is enough for it to turn off. I suspected that the fault or temperature protection was faulty and asked a well qualified tech to check this but they found no fault . Before I take the amp back to the tech , which is a pretty costly exercise, can anyone suggest any other possible reason why this could be happening. Thanks. Cheers Mike Link to comment Share on other sites More sharing options...
Guest Posted March 8, 2017 Share Posted March 8, 2017 I repair amplifiers. I think the most likely cause would be an intermittent fault (possibly a dry joint) or a leaky capacitor in the protection circuitry. I recently repaired a Parasound 855A amplifier that had exactly the same symptoms as you describe. There were four(!) faulty components in the protection circuit: a half open bridge rectifier in its power supply, an intermittent fuse, and two leaky capacitors. Any one of these four items was enough to cause the protection circuit to malfunction. Luckily for both me and the client, I soak tested the unit for long enough to find all four faults before handing the amplifier back. My experience shows just how difficult it can be sometimes, so don't be too hard on your technician. I'd suggest you call Bosko Tadic (Head of Service) at Qualifi and ask who he recommends in Victoria for NAD. Best of luck. Link to comment Share on other sites More sharing options...
Ando Posted March 8, 2017 Author Share Posted March 8, 2017 Thanks John, Its always hard to find intermittent faults and as its pretty hard to think of any other explanation the amp will go back to the tech. Cheers Mike Link to comment Share on other sites More sharing options...
scuzzii Posted March 8, 2017 Share Posted March 8, 2017 I had this same issue when I had a M3. I sent it to NAD and quickly resolved it. Be assured it's a fault they've seen before on that amp. BTW- great amp!Sent from my SM-G925I using Tapatalk Link to comment Share on other sites More sharing options...
Ando Posted March 8, 2017 Author Share Posted March 8, 2017 Thanks Scuzzii, Yes agreed its a great amp . Looking forward to having it back working reliably. Cheers Mike Link to comment Share on other sites More sharing options...
betty boop Posted March 8, 2017 Share Posted March 8, 2017 maybe get it across to nad as scuzzi has so can rectify. sounds like something they are aware off. I owned a m3 for some years and never saw the issue though... Link to comment Share on other sites More sharing options...
PeteD Posted March 8, 2017 Share Posted March 8, 2017 I had that exact same issue with my 2 year old NAD C375BEE. Both the dealer and the warranty agent could not reproduce the fault - they even visited my home and tested my speakers and cables to rule out something in my environment. At the end of the day they took back the NAD and gave me a new Yamaha A-S1100 which I am very happy with. But I will probably go back to NAD if I can find a nice used M3 - I am not a fan of NAD's latest products due to the amount of digital / software stuff going on. Give me a nice and simple analog amp any day. 1 Link to comment Share on other sites More sharing options...
Festooned Posted September 23, 2017 Share Posted September 23, 2017 (edited) @Ando How did you go in the end? Did you manage to have this issue with the M3 resolved? Edited September 23, 2017 by treuben Link to comment Share on other sites More sharing options...
Ando Posted September 23, 2017 Author Share Posted September 23, 2017 @treuben The issue seems to have been resolved. The amplifier played up once straight away at the repairers. The tech gave the amp a good clean inside and left it on expecting the problem to reappear. The amp stayed on at the shop for 6 weeks and never played up again. I have since had it home for nearly 6 months in constant use and no further problem so it seems to fixed. Cheers Mike 1 Link to comment Share on other sites More sharing options...
Bernard Posted September 23, 2017 Share Posted September 23, 2017 I had the same problem then check the power cable which seems not inserted properly. Once I pulled it out and reinstall had no problem at all. I check also the software which needed an upgrade. 1 Link to comment Share on other sites More sharing options...
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