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I went to work last night trying to solve the HV problem (for lack of a better term) and things just don't look good to me. First I looked for a ground strap off the crt. There is a metal shield around it so its hard to see much but I do see the ground spring and it looks okay. I cannot find any evidence of any strap from the crt or shield to the chassis. Since this is a metal cabinet set it would appear that maybe it would just be grounded that way? I installed one of the chassis bolts with not change. (also tried a jumper wire from the shield to chassis) I then swapped the horizontal output tube (and reworked the tube cap, since it had some corrosion) plus the 3A3 and 6BK4. No changes. What I am getting is a real fireworks display in the neck of the crt and this worries me most of all. I hooked it up to the B&K tester and I have good emissions on red & blue but none on green. (odd that with the set running the green gun is active) I show no shorts in the intial test on the machine but when I flip it to clean/balance the heater light comes on. Doing this operation on the green gun made no real difference. I thought this might be a heater/cathode short so I cut the heater wires off the chassis & hooked it into a seperate 6.3vac power suppply. This changed nothing, I still get the light show. Sad, the crt seems so strong otherwise. Could something external be causing this arcing? It is intermittent, only pattern is it has to warm up for a minute. Tapping the neck has not helped, at least not for more than a second or two.
Here is a view of the neck while it was acting up. I would like to think this is not crt related but have no experience with this particular problem.
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Bryan
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