My Renegade is exhibiting fluctuating output at both channels and at both wattage settings. Any ideas why?

[vbf]

I was playing today and my Renegade started exhibiting fluctuating output (quiet to louder the quiet again), which has never happened before. It happens on both channels at a both 16W and 65W. My first thought is a preamp tube may be going bad? Possibly the output transformer? Any suggestions on where to start looking?

TYIA

 

[chumbucket]

Try some Deoxit on the effects loop jacks.

 

[vbf]

Try some Deoxit on the effects loop jacks.

Thank you. Is this stuff the same as contact cleaner or something better/stronger?

 

[chumbucket]

Thank you. Is this stuff the same as contact cleaner or something better/stronger?

It's a contact cleaner and deoxidizer. Just spray some on an instrument cable plug and run it in and out a bunch of times.

https://caig.com/deoxit-d-series/