My amp plays fine for 10 minutes or so then suddenly stops and the green power light turns red. The unit doesn't feel hot at all and the speakers are not having wiring problems. Any thought?
This a common problem with NAD amplifiers.
The caps dry up.Look on the protect pcb, this mounted verticaly near the rear of the main pcb, it has a metal frame around it.
Check the 4 x 10000uf smoothing caps, if the tops are not flat, they will need to be replace with 100volt ones.
Also on the right side of the main pcb around a couple of heat sinks there are other caps which dry out.
You have to remove both output modules to remove the main pcb as there is limited access from underneath.
Best of luck
John
Hey, check speaker connection as informatica says. Also i have experienced that nad 216thx, 218thx, etc has problem with bad soldering on the psu pcb i the buttton of the chassic, chaeck for bad soldering on this pcb. Might do the work. i have a schematic, one channal only, on my homepage www.miguelovitch.dk best regards michael miguelovitch
The problem should be few bad electrolytic capacitors inside the protection circuit. It cause the unit go to protection mode.
I suggest rechecking the speaker wiring in case there is a small "whisker" of wire touching either the case or adjacent terminal, also check the speaker end of the wires for same. Do you have a pet? I have seen wires chewed partly through by cats (& rabbits)! See the information from the manual below: http://207.228.230.231/manual/NAD-C370.pdf
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The unit goes into protact mode ie; red light with or without speakers.
I suspect the protection circuit could be faulty as the sound (when working) is good.
Have a similiar problem with a rather old NAD c320 amp which I am usuing as a switching box and gateway connecting to the graphic equalizer and 2 NAD THX 218 amps in bridge mode.
This problem has been developing over the past year or so in a more or less prgressive manner.
The c320 will either be turned off or cuts out (I have the whole system wired to a motion sensor on/off delayed relay switch). When the unit is switched back on it will immediately go into protected mode (which will last anywhere from 20 minutes to several hours before it suddenly resumes functioning properly).
I've had the unit out to the local tech guy who seemed unable solve the problem for me. Would very much appreciate some advice here...is the problem repairable or should I just invest in a new unit. Many Thanks in advance for any help.
Alex
BodyWorks Fitness Centre
Guernsey
I have a similar problem, the unit trips the protectin circuit when first turned on, after 10 minutes the light goes to green and works fine as long as I dont turn it off.
The local tech looked at it and said 2 of the large filter caps are fried along with approximatly 38 small caps are cooked.
He also stated the overall design is poor with low heat rated caps in close procimity to resisters etc that generate heaps of heat.
The end result is approx 5 hours tech time to repair, cheaper to buy a new amp, DONT THINK IT WILL BE AN NAD THOUGH.
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