John Noll wrote:
Scott Dorsey wrote:

Before doing anything, check the voltage across C12. If the power supply
voltage is off, nothing will work properly, and that's a convenient place
to check the supply rails.

Reads 27 Volts

That's good.

The bias voltage you're setting turns Q1 on, which turns Q3 on, which
turns Q4 on, which turns Q5 and Q6 on. Any one of these transistors
can be bad, and the collector resistors on them can be bad as well.
Check the collector resistors in circuit with a meter; you should be
reading something lower than the rated resistance on each one.

R8 (68k) has no reading in circuit. I replaced it, still
no reading. Reads open with Diode test.

You may need to replace your test probes. Try pressing really hard into
the solder. Or, you may have a cold solder joint there or a broken trace.

I'm suspecting Q1 and will try replacing Q1-Q4 as
suggested by Chris H in following post. Thanks to Scott
and Chris.

The diode test function on the meter will at least give you a ballpark
indication about whether it's okay or not. If all three pins are shorted,
it's definitely bad. If you don't see differing voltage drop with differing
polarity, it's definitely bad.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."