Mains Power Trafo Humming

[sr1200]

and vibrating the chassis of my old gk800rb bass amp head.  I thought the hum problem was from old filter caps, so i replaced all of them (huge suckers, 6 of em and 4 smaller ones).  But after replacement, the hum didn't go away.  I noticed while replacing the caps that a couple of the screws were OFF the transformer mounting holes that connect to the chassis.  I put new screws in, tightened everything in the chassis, now the whole chassis is vibrating (can actually see/feel in the rack ears).  It sounds like its coming from the mains trafo.  Any kind of dummy quick fix for something like this or is it new transformer time?

 

[CJ]

put a C clamp over the top and see if the hum changes,

if it does not, then it might be a loose coil, in which case you can unwire the xfmr, pop the end bells and shim up the coil with a sliver of wood with one end beveled to form a wedge.

 

[sr1200]

Its more of a wrapped up with black cloth like tape job. no end caps.  Lams are exposed around the whole thing.  I did some research and found that GK wound up going with a Torroidal trafo later on in the production runs.  the schematic doesn't show the secondaries on it but after rectification and smoothing, looks like im left with +/- 15 +/-60 and +/-85 volts with the +/-15v being drawn from the 60V rails.