I am a guitar maker wanting to get into some amp work and my first project is to bring this Peavey back up to snuff to use as my shop amp.  Here are the problems:

After 10 or 15 minutes it starts to lose signal (volume goes down and sound gets thin) and then it goes out completely. 

The reverb does not come in unless you kick the amp and get the springs to move and then the control is not even.

I have the schematics and the users guide. Also does any one know of a demo or tutorial of a safe way to discharge the caps on this amp prior to getting in it?

Thanks for your help!