Ampeg B100R again...

[g1]

IC1 pin1 you have 0VDC, yet at pin5 you have +12.8
I don't see any path for DC to be coming in between those 2 points, so not sure what is going on there.
If it is socketed, just pop it out and see if pin5 still has the DC voltage on it.

[Enzo]

There is always the internal path. If IC1 is internally shorted, od voltage can appear on an input pin.

[mtlbasslad]

With IC1 removed Pin 5 is at +16VDC.
Again interesting red peak LED (D1) no longer lights up, although green signal LED flashes briefly at turn-on...

[Enzo]

I see no path for DC to pin 5 absent an IC. ANy chance you have a solder bridge somewhere?

[mtlbasslad]

I thought I had checked that when I installed the socket, but with my shaky hands & poor eyesight there is certainly a chance. I'll check again.
Thanks for not giving up on me.

[mtlbasslad]

No continuity between any combination of pins at IC1. Only Pin 10 is grounded, as it should be if I read schematic correctly.
Self esteem at a new low LOL.

[g1]

Do more checking with the IC1 removed. Any DC on the gain pot P1 ? Which side of R10 has more DC, or both sides same?

[Enzo]

A short need not be on the socket, what if the trace to pin 5 is next to some unrelated trace from somewhere with 16 volt on it?

[mtlbasslad]

@ g1 no DC on gain pot P1... forgot to check R10 sorry - will check after dinner

@ Enzo found a little whisker of solder around IC1 and...

TP2 is now +0.04 TP3 now -0.03 Pin5 IC1 now +0.02 and peak LED no longer on - is this progress?

[g1]

That's great progress. You don't have to worry about DC on the P1 pot or R10 anymore.

What are DC voltages at TP's 4,5, &6 now?

[mtlbasslad]

Well, between messages I tested P1 - no DC... & R10 was 0.037 one side & 0.048 other side. These are really small resistors, 1/8 watt?
Going back out again for TP 4 5 6

[mtlbasslad]

TP4 +9 TP5 +19 TP6 +19 - so no change there...

[g1]

With IC1 removed, what is DC at pins 12,13, and 14, also TP5 and 6.

[mtlbasslad]

IC1 out - Pin 12 0.0V Pin 13 0.0V Pin 14 -0.14V
TP5 +4.6V TP6 -7V
I spent an hour studying the schematic - all I learned was I should stick to tube amps, sigh

[g1]

Well, the good news is that IC1 pin14 (TP4) seems to be causing the IC2 problems, so once you get TP4 straightened out, TP5 and 6 should be good.
Forgot to ask for IC1 pin 12 and 13 voltages with IC1 installed, please measure them.