I had my Comet fully up and running but after a while the displays dimmed to almost nothing. Then I had only 2 showing some segments, but finally nothing. When I test voltages, my -100 is about -25. What is odd is that if I unplug the connector at the display board, I still get -100. It only drops when I connect this. Does anyone know what would cause this? Thanks

Also of note, if I disconnect all the displays the display board still drops this voltage when connected. The 1M resistors all show about 2.9M also. Not sure what is causing this.

Apologies. I gave up too soon. Just found my issue in a repair article. It was r1 or r4 on the ps.