fender reverb tank

My amp pops when I play a G#. It also hums when I use reverb. Any suggestions?
The amp is a solid state transistor amp (for guitar of course).
It will pop or make fizzing noises when I play a Gsharp anywhere on the fretboard.
The popping occurs with every guitar I own. (Which means it has nothing to do with the guitar)
The popping also occurs in both inputs and on both channels (the second with the drive knob at 0).
I own several cords for my guitars, all of which produce the sound (therefore it has nothing to do with the cables).
The hum ONLY occurs when I turn on the reverb. Therfore, it is NOT a grounding problem. I have tried switching the plugs to the reverb tank to see if that would remedy the problem, but it didn’t.
My amp is a Fender 90 Deluxe (not the DSP version).
Dear Yahoo Mods: Yes, I already posted this, but with horrific answers. Please don’t delete this.
get a new amp. Like at Guitar Center ask someone there about why that happened and ask for one that doesnt do that.
Gibson Melody Maker; Fender Reverb Tank; AC15TV HW – Nachos