Problem with my amp.

[Blisterfinger]

So, I've had by Crate BT100 for about 4 years now and it's been working brilliantly up till recently. It seems that every time I plug in a play, the tone/levels changes erratically. I'm definite that it's a problem with my amp but can't narrow exactly what's up. I'm kind of peeved as I've have a practical exam in a few weeks and although I have another amp, I prefer the tone I'm used to getting from this. Does anyone use this amp and if so, have you had any similar problems?

[Muckaluck]

I've had this problem when a pre-amp tube was about to die, but I think this amp is all solid state. Sounds like time to take it to a tech. At least if you take it in now and get it repaired you could have it for your exam in a few weeks.

[Rick Auricchio]

If the amp has effects send/return jacks, try cleaning them. The easiest way is to turn it off, then run a standard guitar plug in and out of the jacks to exercise them.

Even better would be spritzing the plug with a bit of contact cleaner before doing the old in-out. Don't spray the cleaner into the jacks, just on the plug.