Arcing around neck board

Likom ViewMate LP995 19 in. CRT several years old. Powers up OK, but hear "snap" and video drops until recharged, repeats. Took off cover, flash of arcing around neck board, not sure, but looks like might be arcing inside CRT tube's clear neck. Is it an over-voltage problem, or is the CRT tube bad, or...?? I have a HV probe good to 40kV, would it help to measure a voltage somewhere?

Anonymous May 31, 2007

As I remember, the arc-flash came from the white CRT socket at first (upper right picture). Inside this CRT socket is a dual spark-gap over-voltage (bottom picture) protection. I had disabled this spark-gap, thinking something had gone wrong with it (obviously not), and now it arcs in the tube (upper left). Do you maybe think that this is an over-voltage problem? If so, is there anything I can do?
Anonymous May 31, 2007

I should add that the monitor displays perfectly in-between the HV arcing, so there must still be a good vaccuum in the tube.

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There is a crack in the neck of the tube and the vacuum inside is lost. There is already air inside the tube that is why the sparks are going to the pins. The TV must have been dropped or someone accidentally hit the neck of the tube

Posted on May 31, 2007

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24 seven is probably dead on. CRT is likely gassy. While an overvoltage condition is possible, the overvoltage sense circuit should shut the Hi-volt circuit down, and you'd have no Hi-v or display at all. With the availability of good used monitors & flat screens, repair is not economical at all.

Posted on May 30, 2007

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Sounds like bad crt if you saw arc inside glass...no economical fix-replace the monitor

Posted on May 30, 2007

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