Acoustisonic Jr hum....

[mmrxcsr01]

Morning all...Acoustasonic Jr, PR334, has a slight hum on powering up. The owner says he THINKS it goes away after a few minutes, but I don't have it here to verify. Would it be reasonable to look at the filter caps, given the age of the amp? Production was around   2012/13....again, I have no solid state troubleshooting experience, just tube, but trying to help out a friend. Thanks in advance for any suggestions...

https://www.manualslib.com/manual/452549/Fender-Acoustasonic-Junior.html#manual

[shooter]

I would start will all the jacks, especially the ones that "ground" when nothings plugged in.  Also more information, like does it hum at your house, or his garage?  (change environment)
what knobs effect the issue, info that can help guess where to narrow down the issue

[mmrxcsr01]

Thanks Shooter, I know, not a lot to go on. Here's what I got from the owner this AM, I'm hoping to get the amp this weekend....

"Turned on.  Heard a rhythmic, very slight pulsing noise, co-incided with the "Chorus On" activated---the light pulses low-to-bright every second or so when activated.  Turn it off and the slight pulsing goes away. A minute later, the hum sound appeared.  Constant hum.  Does not matter location, direction, whatever.  Grounded plug, so no change in polarity.  All the while the amp functions well."

I'll take a look inside when I get it, and check the jacks/grounds/solder joints, etc. Thanks for your time....

[shooter]

the amp has a send/return, if you get to tinker, that's a good place to split the system in half.
there is a chorus bias adjust, but you'll need a scope n sig-gen.

I would start with a good round of contact cleaner, wiggle-jiggle the connections on the board.
be careful, PC stuff has a tendency to get worse the more you F with it

[PRR]

.

[shooter]

 
that in-line one kept hurting my face

[mmrxcsr01]

Shooter, PRR- thank you gents...