Fender 68 Custom Deluxe Reverb noise issue

[The Dude]

Oh man, if only I could remember. I must be experiencing some brain fog right now. I worked on one of these with the exact same problem a few months ago battling it for quite a while. I know that I fixed it, but I can't, for the life of me, remember what the solution was. If I come to access that particular file cabinet in my brain, I'll chime in again.

[Tom Phillips]

... I am going to take a closer look at that and see if there might be a broken solder joint in there somewhere. It looks like they used those bracket pots, and sometimes they used to use those to jump grounds over the other traces. Maybe one of those got flexed too hard.

I suggest that you also take a look for any mechanical ground points at the front end such as under screw heads and, if there are any used, make sure that the surfaces are clean and tight. I also wonder if there is a bad switching contact in one or more of the input jacks. To test for that without removing the control board, I would insert shorted 1/4" plugs into the inputs to determine if the noise stops when all the inputs are hard shorted to ground.
Hope that makes sense and good luck with this frustrating issue.

[glebert]

Think I have this figured out. The ribbon cables that go from the main PCB to the front panel PCB (where the pots and jacks are) have awful retention. The pins feel really sloppy in the connector sockets, the bump that is supposed to be a mechanical connector retention is more of a suggestion, and there is no glue or anything to keep the connector seated firmly. Also, the orientation of the ribbon cables is such that they tend to push the connectors up and off the pins.

Will let the shop manager talk to Fender and see if we can just hot melt glue them down or if there is a better approach.

Thanks all for ideas.

[Helmholtz]

Make sure there's enough contact force by retensioning and clean contacts with Deoxit.
If that doesn't reliably work, the female connectors should be replaced.