AMP is dead quiet when I pull the amp

[Michel Bevan]

Hi,

I picked up a NAD 3020A amp. When I turn it on, a loud hum sound comes through the speakers for a second and then fades off. The problem is in the preamp section, as the amp is dead quiet when I pull the amp/preamp jumpers and turn it on. All of the pots have been cleaned. The amp works fine after the hum goes away. Someone suggest me the pre-out muting fets leak. J111 is generic so I looked here https://www.icrfq.com/part/2000795-J111.html for J111 and I got it here. I do not have a schematic for this unit. How many fets should I purchase, and where do they go?

Any suggestion will be appreciated.

[Daryl Kosinski]

I have retired from servicing industrial electronics for 39 years. With that said. Unless you understand the safe handling of static sensitive components (most are ) and have a static safe work area. Good soldering skills are also needed. leave the replacement of those components to the pros.

[David King]

Daryl's advice is good

You might have more luck at the music electronics forum but last I checked NAD made home audio equipment so you might have even better luck at a home audio electronics forum. MEF is here: http://music-electronics-forum.com/forum.php
Check out http://audiokarma.org/forums/index.php? ... ds.426532/

[Michel Bevan]

Thanks for sharing. It's a very nice information for me!

[Julius Miles]

Daryl's advice is good

You might have more luck at the music electronics forum but last I checked NAD made home audio equipment so you might have even better luck at a home audio electronics forum. MEF is here: http://music-electronics-forum.com/forum.php
Check out http://audiokarma.org/forums/index.php? ... ds.426532/

I have used MEF for a long time and can comment on how great some of the users there are. That place is a wealth of information.