My mesa is under the weather

[moltar]

When playing my boogie has ben unexpectedly losing volume. It will sometimes return to where it should be but I have found no way to control what is happening.

I suspected it may be the tremolo switch acting up again but the problem continues even without the footswitch. The amp was also running for a few days on a groove tube replacement tube, but still exhibits the same problems with the original tube.

Ah! I had just tested and found the volume was jumping in both the lead and contour channels so I tried the clean. I got fuzz, static, and almost no volume!

 

[moltar]

I'm still trying to pinpoint what's going on here.

So tonight I was testing the guitars and cables on my Rocket 440. I got similar results with all combinations. The volume feathers around randomly and much bellow where it should be. Also I get a static buzz on occasion when playing on the clean channel. I took the metalic covers off the pre amp tubes to see if any were running too hot and the amp worked flawlessly the rest of the night.

If anyone has similar experiences or helpful advice, hook a brother up.

 

[Buddy]

When is the last time you gave your amp a " tune up " .
Like cleaning the jacks , pots , tube pins etc .
I do it once a year and eyeball the components for any discoloration or buldgyness . Remember to unplug from power and discharge the caps . :wink:

 

[moltar]

Never have. How do you safely discharge the capacitors?

This is not something I'm fully considering doing myself. I may pay some extra for an amp tech to give me and overview of what to look for and check while they get me repaired.

 

[Buddy]

I use test clips with a resistor soldered inline . Go from the cap lead (+) to the chassis . Leave in there for 5 min or so .

Check for discolored resistor's, buldging cap's , fried diodes , melted wires and so on . Remove dust and dead bugs \ mice . Buy a can of DeOxit for the pots .

Yeah, I found a petrified mouse in a unit that was in for servicing .

Toasty!