Music man 2275-65 ss phase inverter issue?

[parentheticalfact]

Hello all! Haven't posted in a while but I wanted to see if anyone could help with a music man 2275-65 I have on the bench.
This amp only puts out a very tiny amount of signal. Someone had stuck 6L6's in it so I promptly put EL34's before doing much with it.
This amp has the solid state phase inverter and when the trim pot is turned counter clockwise from the back of the amp, the amp picks up in volume but not to any substantial glory. The other direction the amp reduces greatly in volume. Is this control not a phase inverter balance of sorts?
Just wondering if anyone has any better understanding of this phase splitter circuit and might know where I should be testing for voltage on it.

[oc disorder]

Um thats the bias control for the 2 x JE 1692 transistors (TR1 100ohms).
This should be adjusted to give 25mv across (MAX 55mv) the two 3.9ohm
emitter resistors R56 and R61.
The other trim pot is for the tremolo.
Its possible one or both of the JE 1692 transistors are kaput !
JE1692 = 2N 6488 TRANSISTOR SILICON NPN / 50V / 15A / 75W
Check the diodes D15 and 16 too but in my experience it has always just been transistor failure in that area.
IC 8 is inverting the phase.

[Bernardduur]

Great info!!! I have one other on the bench (a 2165 RP) that has the same issues; one of the transistors is done I guess as one of the emitters is not biasing.

Will try to replace em; btw, there is no other BIAS on this amp??? Just really unsure because of the amp's weird design!

[J M Fahey]

one of the emitters is not biasing

What does that mean?:

*not responding to bias pot ? (bias voltag does not change)

* zero bias voltage?
which might mean:
a) open transistor
b) shorted resistor

* something else?

otherwise it becomes the dreaded "no measurement/measures nothing" statement which actually means nothing.

[Bernardduur]

It did not respond to the BIAS potmeter. I replaced the transistor with good effect