Beware of NAD M3 Fire Hazard


My $3k NAD M3 started shooting sparks out the top and burned the shelf that was 8" above. Luckily I was home and not sleeping or the house would have burned down. If anyone has one of these I advise them to unplug it when not in use. I took it to two different repair shops and they said it would be about $800 to just get it running and there may be board issues. They advised not to take the gamble. Anyone have any suggestions on what to do with it?
pwb
@ pwb

Odd the AC line safety fuse did not blow. The fuse should have blown protecting the unit from becoming a fire hazard. Is the AC Line fuse the original OEM fuse that came with the amp?

If it is the original OEM fuse I suggest you contact NAD service Tech support.

Jim

Have you removed the ground pin?
If not, check that your socket is correctly wired.
Odd the AC line safety fuse did not blow.

@jea48, Jim, I took a look at the service manual for the M3, which can be seen at hifiengine.com if one is registered there. It appears that it has three fuses, all of which are AFTER an EMI filter, consisting of inductors and capacitors, which is connected between the incoming AC and the rest of the amp.

There are two 5 amp fuses (assuming this is a 120 volt model), one for each channel, with the main (rear panel) power switch connected between the filter and these fuses. There is also a 100 ma fuse protecting standby-related circuitry, with a relay connected between the filter and this fuse.

All of the fuses are located inside the unit, and they are not accessible on the rear panel.

All of this would seem to cast suspicion on the EMI filter as the culprit, although secondary damage elsewhere within the unit certainly may have occurred.

Best regards,
-- Al


Did the service manual indicate the correct fuse direction? Might have been switched.
Thanks for the responses. As far as I know the fuses are intact. I stopped the sparks shooting out the top by unplugging it. I took it to the NAD authorized repair facility and they said a faulty power supply caused the round cylinder ( not sure of part name) to explode which probably damaged the board and other parts. I can send pics if anyone wants to see the damage. Thanks.