Was about to demo for sale my ol trusty '68 Fender Bandmaster Reverb head, had just shown it a couple months ago and it worked fine. This time I turn it on with switch in Standby and it immediately blew the 2A Slow Blow fuse. Put in another fuse and this time watched the GZ34 rectifier tube and the two 6L6's and on power-on I noticed the rectifier tube was arcing like a Mid-west Lightening Storm at the top inside and one 6L6 (the 2nd to the right) was dead with white powdery residue on the top of the (upside down) 6L6 tube and on the side of the tube across from the cathode.
I've never had this happen to any of my vintage amps, so I'm shocked (excuse the pun).
Any Amp Techs have an idea what happened?? Blew a Cap? Xfrmr?
Can I diagnose and fit this my self - pretty good with a DVMM. Any diagnosis / repair guides online?