Determined to fix 93 Blues deluxe

[tbrogit]

I still have a clean channel volumn issue that I am determined to fix. I completed recomendations for upgrades to R71, R85 and R86. The -16+16 zenors seem to be working as intended. Ive upgraded r71 to a 1/4 100k value. Ive cleaned the back of the board for excess residue. Ive resoldered all primary connections such as pots and jacks. But I still have this issue with the clean channel volumn pot being wide open. It tease me too as I can turn the amp on for a few moments and the clean volumn will work as intended for a few and then go straight to wide open with a noticable increase in noise and hiss. Almost as if a ground has lifted. I feel pretty confident I can rule at the pot itself. As it works sometimes. I would like to start taking some measurements but dont know where to start.

[Jazz P Bass]

Fender Blues Deluxe Service Manual

I would be looking at the RY1A relay & the associated components.
If it drops out, there goes the volume control ground reference.
Also monitor the actual 16 volt voltages. + & -.
Don't assume the repair that you did is good.
Verify it.

[Enzo]

I won't assume the pot is good just because it works sometimes. Pots can be intermittant like anything else. And just because you soldered it, doesn't mean teh pot has a solid connectin all the way to ground. A junction elsewhere could be doing it, or a copper trace could be cracked.