The 2204 is down.

[ViperDoc]

AND NOW IT WORKS!

All of your help is much appreciated. Sluckey, man, thanks for helping with the 106R diagnostic on the choke. That made all the difference. I can just see it now--pulling the whole amp apart, replacing it and having it work--with all the confirmation bias and wasted time and money. Thank you.

All I did was pull the solder off the lugs, re-trim the choke, fuse holder and can cap lead wires and solder everything back together. The only thing I changed was I re-routed the screen resistor leads away from the heaters as opposed to directly over them as I had originally. The amp sounds just fine now.

The only thing that makes sense to me is I had a solder joint go bad on the fuse holder, the choke, or the second can cap ground. No voltage potential was readable on the second can cap at all. What was also odd was since the failure, the first can cap would hold a full 450 VDC until I drained it. It usually will only show 4-10 VDC after a full power-down. Why would that be?

ANYWAY, guys and ladies, thanks a million for your help, as always. CHEERS!

[martin manning]

The only thing that makes sense to me is I had a solder joint go bad on the fuse holder, the choke, or the second can cap ground. No voltage potential was readable on the second can cap at all. What was also odd was since the failure, the first can cap would hold a full 450 VDC until I drained it. It usually will only show 4-10 VDC after a full power-down. Why would that be?

One or other of the choke connections had to be open. Hard to believe that you wouldn't get any voltage through. Re the cap holding charge, if there is nowhere for it to drain, it will persist for a long time. The open connection left no path to ground. Take heed, this is a good example of how an amp with an unknown fault can be dangerous.

[ViperDoc]

INDEED, Martin, many thanks!

There's clearly more for me to learn here. That both can caps are chassis-grounded and can still hold a massive charge leaves me a bit stumped initially, but I guess if the the + is disconnected, the open circuit allows the cap to hold the charge. Scary, man!