On 13/04/2010 13:01, Phil Allison wrote:
"David Harris"

My trusty old NAD 3020a has stopped working properly. Prob somewhere
between vol control and preout/in. Suspect J111 muting FETs.

** Suspect bad contacts on the pre / main links too.


I have a reasonable copy of the cct diag, but cud really use a PCB layout
to help me finally fix this.

** All you really need is a well trained nose for all the usual culprits
built into most cheaply made amps.

Cos NADs have every last damn one of them.


l probably replace all those old drying caps while Im at it.

** Make that a 100% certainty.

Got an ESR meter??

Be amazed how many small electros are totally stuffed.



.... Phil



Thanks for all those pointers Phil, but it was actually a dry joint on
the cap (47u 63v) in the FET mute control circuit. It was causing mute
to be on permanently. I sussed it by judicious prodding But u are
right, and I am embarking on a cap swap out project over the next few weeks.

I still wouldnt mind a layout diag though if anyone has one ?

DH