Hi,
Over the past few days I've been analysing a problem in my Eizo T766 19" CRT (Sony Trinitron tube), with this group's help. Unfortunately, I can conclude nothing else besides that the red and blue gun occasionally short to something at low potential, most likely the heater. I tried tapping it loose, but with no success. So, now I'd like to collect as much information as possible about zapping the short out.
I've seen suggested that you can use a neon transformer (or other kind of tesla coil) for this: connect both pins of the heater to eachother, and connect the transformer between it and the affected cathode (one at a time). This seems rather dangerous to me; such arcing usually leaves everything blackened. If this is a good approach, what voltage neon transformer should I look for?
Another method is a capacitor charged up to several hundred volts; start with a few uF, then increase as desired.
I would like to know, based on people's experience, how much chance I have of blowing out the cathode or filament. Bear in mind that it's an intermittant short, that does not show up on the DMM when the tube is unpowered (not even on the 200 MOhm range), so in the most positive situation, we're talking about loose debris which needs to get out of the way, and not a dead short.
One last question: is the heater filament an exposed (or covered?) fragile filament like that in light bulb, or is more robust like heating wire of an electric stove?
Any help is appreciated, and thanks in advance.
Wiebe Cazemier