I have a VGA tube that was pulled from an old Tektronix TDS510A. It's now being used as a little monochrome VGA monitor. Discovered a weird issue after its been running for a while. The picture slowly expands, then the screen goes blank.
I am driving it with a 640x480 VGA signal at 60Hz refresh
Never seen this before. Could it be capacitor related?
video of issue
Video is without crt turning off.