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Nad 3140 Clean up and repair.

0.68uF and 1uF WIMA film MKS2 will work.

Yes, change them. Because they can and do go bad.
 
I'm stumped on something guys. I can't identify where TP1 and TP2 are to perform the Idle Current Alignment.

There's no TP1 or TP2 label on the PCB (either side). Am I supposed to put the probe on a solder spot someplace on the back of the PCB?

Scott
 
Scott Frank said:
Thanks Lee. I can't find a Nichicon UKL 1uF 16V (or even a 50V) that's in stock at Mouser or DigiKey. And can't seem to be able to identify an appropriate film cap either. Would you happen to have another suggestion?

Also, given this type of capacitor (low leakage current) should I even be worrying about replacing it? I'm assuming they age like a typical audio grade capacitor but that may not be the case...

Scott
Click to expand...

It doesnt have to be brand specific. Just stay withing the tolerances of the current cap and it will be fine.
 
Scott Frank said:
I'm stumped on something guys. I can't identify where TP1 and TP2 are to perform the Idle Current Alignment.

There's no TP1 or TP2 label on the PCB (either side). Am I supposed to put the probe on a solder spot someplace on the back of the PCB?

Scott
Click to expand...

You need to measure across the emitter resistors. I would suggest soldering a couple of pieces of scrap wire onto either end, so you aren't poking around on the board.
 
Trying to get one like this going, only its not using the TO-3 type motorola transistors. It looks like the left brace was discarded or lost. From what I can tell there is only one foil connection to it
on the top, and it seems to go to all the input jack grounds. At one point I had it working with new Sanken output transistors, then I removed a jumper and forgot where it went and it stopped working.
Got that problem resolved and I wired that foil to the chassis with a ground lug on the other brace. Before I test, is this ok or was that brace only found in the early versions with that transistor setup?
 

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