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

hehe31 · 21st December 2007, 10:19 AM

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

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 · 24th January 2008, 03:20 PM

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 · 9th March 2008, 12:45 AM

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 · 13th March 2008, 06:43 PM

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 · 13th March 2008, 10:03 PM

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 · 4th February 2011, 05:08 PM

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

Mooly · 4th February 2011, 06:03 PM

Quote:

Originally Posted by forbinnie

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

21st December 2007, 10:19 AM	#1
hehe31 diyAudio Member Join Date: Sep 2007	Help me to fix my nad c320: need a res value My nad c320 amp looks broken: The power led stay red (protection) Inside a resistor is burned, i can't read the value: 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?

Thread Tools	Search this Thread
Show Printable Version Email this Page	Search this Thread: Advanced Search

Similar Threads
Thread	Thread Starter	Forum	Replies	Last Post
Nad c320 service manual	crazy_bob_uk	Solid State	9	20th April 2011 07:51 PM
nad c320	reddish75	Solid State	3	16th September 2008 02:05 PM
NAD C320 Amp Protection delay help please	Kajman	Solid State	2	15th December 2007 03:24 PM
NAD C320 secondary winding voltages?	skenwrick	Solid State	0	8th February 2006 09:29 PM
Nad C320 Psu?	skenwrick	Solid State	0	3rd February 2006 02:37 PM

New To Site?	Need Help?
Register to Participate Search Privacy Statement Contact Us	Frequently Asked Questions Did you forget your password? Mark Forums Read


	Please consider donating to help us continue to serve you. Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving

24th January 2008, 03:20 PM	#2
al1 diyAudio Member Join Date: Aug 2007	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?

9th March 2008, 12:45 AM	#3
Kajman diyAudio Member Join Date: Jan 2006 Location: WILTSHIRE	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.

13th March 2008, 06:43 PM	#4
hehe31 diyAudio Member Join Date: Sep 2007	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

13th March 2008, 10:03 PM	#5
Kajman diyAudio Member Join Date: Jan 2006 Location: WILTSHIRE	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.

4th February 2011, 05:08 PM	#6
forbinnie diyAudio Member Join Date: Feb 2011	Can anyone tell me which electrolytics make up the protection circuit?

Currently Active Users Viewing This Thread: 1 (0 members and 1 guests)