Re: 577 Bad CRT?
I actually included a short compressed GIF demonstrating the problem, notice the pattern of the trace with a transistor under test how each segment briefly flashes with a higher intensity than other segments of the trace. I turned intensity fully counterclockwise where the display went completely black, oddly the flashing segments of the trace were briefly visible before immediately disappearing to darkness.
Also I probed R1218 as shown in the schematic image as you suggested in hopes I would see any occurring spikes, I only noticed a constant DC voltage (no spikes) which would vary depending on the intensity knob setting so I guess the intensity circuit is good all the way up to that point.
The final path to check is before C1242, a 0.01uF capacitor which is holding back 3000V, I will definitely need a high voltage probe here
Thanks for the reply