21CT55 Screen-Shot Test

[Electronic M]

Most makers assumed that a set would not be running for a long time in failure mode...just because you can run an engine for a couple of minutes with no oil or coolant in it without it burning up doesn't mean it won't if driven in that state for a prolonged period.

You've already seen the original and 1 replacement burn up. Shouldn't that tell you to dial it back a bit? Even 3-4KV (lets say a tech had a HV probe that was 1-2KV off and set it for 26-27KV) less than you've been running it at will have only very minor effect on brightness, sweep and general image quality and will be at least reasonably close to factory specifications. Even before the X-ray alarmists many makers in their service literature stressed proper HV adjustment. New flybacks don't grow on trees; why not cherish what may be the last one you can find?