HV Arc on CTC-5

[Yamamaya42]

Originally Posted by Electronic M

If you don't know where the arc is fixing it can be extremely difficult. Sometimes it is worth while to get it to repeat to find it.

Cleaning the dust inside the HV cage is a good start, but don't go crazy on the flyback...if you break a lead off the fly it can be game over for the set.

The front of the shroud tends to stay fairly clean inside, but the area near the yoke can get fairly grimey...if it's arcing in the shroud the yoke end is where I would first look.

The 21AXP is designed t run at 25KV and the weak HV system of a CTC5 is having a really good day if it can deliver 20 with the pull down regulator unplugged....The HV cannot not shoot up to 100KV and saw the neck off the CRT like a Zenith CCII with bad safety caps so the CRT shouldn't be harmed. Flybacks can also take around 10 seconds of arcing (especially when cool) and be okay.

"saw the neck off the CRT"?
That's an exaggeration, I assume? can't really happen... right?
Although, it does remind me of a failure I had in a BarcoData (crt) projector long ago, it had been working fine for months, clear and bright, and suddenly went dark with a loud popping sound , (hv arcing) when I took it apart, I found the HV pcb had failed , common problem on these, but not only that, a tiny crack had been blown in the blue crt, right where the inside dag ended, allowing the hv from the inside to jump to the yoke.
I could not believe what I saw, how THE HELL did that crack get there? It could not have been there before, cause it would have caused vacuum loss.
Did the hv blow through the glass? Perhaps it did...