VCR Gymnast wrote:
The corresponding Test Point (TP) voltages on Servo board 2 are TP7 for
the supply reel and TP9 for the take-up reel. Both should measure 6.00
VDC.

I've got 0.10V for both.

To check the power supply regulator board, here are the TP voltages
that should be present:
TP1: +11.7 +/- 0.3 VDC

I've only got 0.87VDC.

TP2: +9.0 +/- 0.3 VDC

0.04VDC.

TP3: +5.1 +/- 0.2 VDC
TP4: +5.1 +/- 0.2 VDC
TP5: -14.0 +/- 1.0 VDC
TP6: +10.3 +/- 0.5 VDC
TP7: +16.5 +/- 1.0 VDC
TP8: +18.0 +/- 1.0 VDC
TP9: +12.0 +/- 0.4 VDC

TP3-TP9 are all in spec.

TP10: +15.0 +/- 0.4 VDC

-0.003V.

Looks like I've got a power supply issue, all right. At least it's a
linear supply instead of a switcher, from the looks of things. At this
point it would be nice to have access to a schematic; I'm guessing TP1,
TP2, and TP10 are all derived from a common source voltage, somewhere.