Zenith Chromacolor HV issue: Am I goin crazy?

[DaveWM]

I would not every use a tube tester on:
Damper/horz out/HV rec/shunt or regulator tube.

If you are having any HV issues it best to try subbing known working tubes in those areas. I don't think most tube testers can simulate the working environment of a tube, esp those.

I pretty much only rely on the shorts test before installing any new tube just to make sure it does not damage the set being worked on.