Renown 400 Nasty Noise

[kn6xu]

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 with no effect. No other devices were connected. 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

[Enzo]

Wow, you are all over the internet today...

It sounds like a loose main filter cap. It seems to have broken free of its solder. I'd bet my lunch money.

This will require complete disassembly of the amp chassis to get at. The heat sink is held to the rear edge of the chassis by a row of hex head screws. The controls all have to have their nuts removed. Then the board can be extracted, flipped over, and work done on its underside.

ALWAYS work with the power removed. This is a solid state amp, so the most dangerous thing in ther is the 120v mains, but they can kill you too.

If it is not the filter caps, then look for loose screws anywhere inside.

[kn6xu]

Your Lunch money is safe!

That was it exactly Enzo. Who ever had this amp before I got it must have had the same problem. I found a piece of folded up paper jammed in between to two caps and when I removed it one of them was extremely loose.
I continued the disasembly, re-soldered both caps and while I was in there went ahead and hit all the other joints I could get to as well. I put it all back together and this box is pumping out clean sound just like it was brand new. Total time = about 1 hr.
Thanks Enzo!