5150 block letter combo Master vol, tone control's, and reverb inop.

[8wattjack]

1

[PRR]

I can't find R11.

I can't find a "Master". I see two "Post" pots where I would expect a master.

The "Clamp" shorts-out all signal, I assume for a short blip while switching. Unlikely your problem.

[PRR]

> r110 and r111 provide +23v.

OK, so somehow the +23V line got shorted (I don't see anything else likely to blow those Rs). Given what you say about jammed-in, I suspect much of your trouble is "mechanical", not schematic. But I have to sleep-up for snow in the morning.

[shooter]

I suspect much of your trouble is "mechanical",

Yup!!!
that amp is a POS*2 servicing, give me 10 old Gibsons ANY day!! 

on the verb, check the tank itself for broke wires, or spring, cable in/out.

once you get it workin, sell it!!  I've done a couple repairs on the 5150, I turn 'em down now!