Fender Princeton Chorus

[cherokee7]

I have a Fender Princeton Chorus amp and it had developed a buzz or hum! If you tap on the amp it will go away for a hot second and the hum will come right back. Am wondering if anyone has had this problem or any suggestions on what to look at to fix it. I love this amp and would like to see it fixed as it has an amazing sound. Appreciate any suggestions greatly!

[Jazz P Bass]

Fender Princeton Chorus

Take the chassis apart, remove the main circuit board & resolder it.

[nashvillebill]

Specifically, check the solder on the two large filter capacitors, they're about the size of a C flashlight battery. On mine they're labelled C59 and C60 (mine's the red-knobbed version).

I have read that these amps have been prone to hum from failed solder joints on these caps because vibration causes these caps to move around...a big dab of glue can help prevent that.

[nashvillebill]

Here's a picture. They're the two large black "cans". You'll likely have to disassemble the amp to gain access to the bottom of the printed circuit board.

[cherokee7]

Fender Princeton Chorus

Thanks for the info, I have had the assembly out and I am going to take a look at that. Just wondering if the solder is on the visible side or does the board need to be removed and be re-soldered from the underside? Sorry for the lack of correct terms or knowledge. I'm kinda new to this but not afraid to get in there and try and fix something myself.

[nashvillebill]

On these types of printed circuit boards, the components are inserted from one side of the board, but soldered to the traces on the other side of the board. So the board will require removal from the amp chassis.