Help me to fix my nad c320: need a res value

[hehe31]

My nad c320 amp looks broken: The power led stay red (protection)
Inside a resistor is burned, i can't read the value:

An externally hosted image should be here but it was not working when we last tested it.

If someone have the same amp, can he read this value? 🙂

I have the C320BEE schematics but it's different on this part.

Any idea on how to fix this?

 

[al1]

try zeroing the speaker dc offset,i have same amplifier and i accidentally turned those blue trimpots(marginally i guess) and red light kicked off.that resistor is in the pre-amp section just wondering if that could be the cause..im newbie to electronics but had the same expirience after replacing most electrolytic caps with better ones?

 

[Kajman]

The probem is common in the NADC320. The resistor is 1 K ohm. I would replace it with at least a 1 Watt though avoid using a wirewound type.

 

[hehe31]

Thanks for the help 😉
The resistor looks burned but his value is around 1k, but it's hot: 25v between the leads.
power supply look ok, the CD offset is ok on both sides
All the preamp part works good

 

[Kajman]

The resistor is not your problem and I suspect the preamp is fine. The Reserviour capacitors in these amps tend to cause a problem. 2 x 15000uF with 1 2200uF and 1 3300uF The Electrolytics do dry out and may burn out. These will usually affect the protection circuit as well. Replace all the electrolytics in the protection and ISC circuit (Its only maybe 8 in total) and the amp will come alive if the 4 big electrolytics are ok. Can you measure the output voltages from the power supply.

 

[forbinnie]

Can anyone tell me which electrolytics make up the protection circuit?

 

[Mooly]

Can anyone tell me which electrolytics make up the protection circuit?

There are more than just capacitors to a protection circuit.
If you post a circuit it would help... and maybe start a new thread if you have a problem 🙂

 

[Dannomite123]

I recently got a C320 that was stuck in protect mode.
Sure enough it was an electrolytic cap in the protection circuit that was open circuit. I checked the rest of them and found 20 that were bad. Either low capacitance or high esr or both. NAD used some cheap and nasty unheard of brand JH caps in this amp. I replaced all caps with decent ones except for the four power supply caps which tested fine. Works good now, but the sound is not really to my liking.