Swan 700 CX make sure ceramic band switch in finals compartment is fastened down tightl 1/2 inch nut

[@macster11]

You scored as far i can tell the iñside of that is clean. Do you own a tube tester ? Start checking the tubes while looking for ps?

[@dfpolitowski2]

Make sure your the PA plate air capacitor does not hit or come close to the parasitic coil upon opening the Air capacitor. It can and will hit it if the coil grounding out 900 volts if not positioned out of the way.

[@moviestudioland]

Good point David I had an air capacitor fins collide on a Drake TR four on the neutralizing capacitor it ended up blowing up my power supply both sides the high voltage and low voltage got blown out