2018 JP6 buzzing like crazy

[Sorbz62]

I just got a 2018 JP6 in a trade and love it but when I plugged it in, it was buzzing like crazy, diminishing a little when I touched the pots but not totally silent.

I took off the control cavity plate and found a black grounding wire from the jack placed to connect to one of the cavity plate screws but not to the grounding screw. The wiring diagram shows this black wire connected to the grounding screw and a flyaway wire going to the cavity screw. Am I correct?

Everything else looks OK.

Thanks in advance,
Jim

 

[tbonesullivan]

That is the wire labeled "to shield" I believe. it grounds cover for the control cavity.

 

[Sorbz62]

So I soldered the black wire from the jack, which was attached to the cavity plate, to the ground screw and added another wire from there to the cover and it is quiet now!

 

[beej]

Hey that's great! Totally sounded like a ground issue, but it's difficult to tell from the photo. Glad you got it sorted.