Yeah teemuk the problem was obvious once I opened her up. This amp has had this problem for a while it seems. Instead of fixing the problem properly the previous owner decided to "tighten up" the filter caps by jamming a folded up piece of paper between them. I pulled the paper wedge and one of them started flopping around like a rag doll. I went ahead and re-soldered the caps and hit all the other joints I could get to, put her back together and now she's pumping out beautiful clean sound once again. Thanks for the input!

Hello All. Glad I found this board. Lots of good info here! Now for my issue....
I picked up an '87 PV Renown 400 and the first day I hooked it up and played thru it it was great. The 2nd day I started using it again and about 2 hours into a great jam the darn thing cut out and started producing this nasty loud buzz and stopped producing output from the guitar. At first I thought maybe a bad cord so while this noise was rearing it's ugly head I disconnected the guitar cord and the noise was still there. I even disconnected the stock foot switch and the noise was still there. No other devices were connected and none of the controls had any effect. Finally in desperation I gave the thing a whack on top just above the on/off and ground switches and it went away. I pluged my axe back in and continued playing then a few minutes later it happened again. I'm hoping this is just something loose but I've never taken one of these apart before so I thought some input from you folks might be helpful. Any suggestions as well as do's and dont's would sure be appreciated.
Thanks,
Paul