Fender Princeton Chorus trouble

[travisgarman]

Hi, this is my first post on here, so all apologies if I'm doing this wrong.

But, I've come to notice a strange problem with my fender princeton chorus.  After owning it for about 2 months, a problem has started to occur; the amp will sound super muddy and bassy upon turning it on, then with the slightest tap of the amp (or any movement of the amp) all the bass is cut out and the amp sounds extremely bright and very treble heavy.  I know very little about solid state amps and was hoping someone here could help me troubleshoot.

[phatt]

Hi and welcome,,
The most likely culprit will be a cold solder joint,,, finding it is the hard bit.

If you have never worked on these circuit before then simply return it as it should be covered under warranty.  :tu:

To fix it you will have to remove the PCB. I don't know that model but most likely the whole circuit is on one PCB and solder side will be underneath and hidden. To re solder the part you will have to dismantle the whole thing.
Pull the lid,,, Make sure you know where the Mains power cables run and don't touch anything you suspect as mains voltage which may want to kill you 8| . Now with amp on and running some music into the input  take a wooden stick or anything that is non conductive start poking tapping bumping parts on the PCB will often give a clue as to where to find the offending join which will be underside.
Power down and flip the PCB then go look for a hairline cracks on the solder pads,, bright sunlight on the board will help

If the amp has several circuit boards then wiggle those ribbon cables as some are very flimsy and often fail.
Phil.