We found a shorted diode in one of the rectifiers in the +/-42VDC supply in the VR14 that was causing the main fuse to blow. The donor of the PDP-12 gave us a spare so that was an easy fix.
We reinstalled the VR14 in the PDP-12 and ran the display diags. The VR14 display actually works! We found a open trimpot for the gain on the vertical flip-chip. We swapped the horizontal and vertical flip-chips, adjusted the gain trimpot, removed the flip-chip, and added a fixed resistor with the same value for now. The display when running the diags looks very nice and crisp. We booted LAP6-DIAL and could display a listing of the files on the tape on the VR14 monitor. After about 20 minutes of running nicely, the TC12 went back into the mode where it could not find blocks. Oh well, more debugging to do. -- Michael Thompson