At 08:07 +0000 12/28/05, Mark Benson wrote:
I've seen CRTs lose pixels before. It's very rare, but it isn't totally unknown, I think the phosphors burn out in one spot with age. May originally have been a manufacturing flaw.
A common problem with CRT's is a timing failure that allows the electron gun to operate when there is no raster being generated. The result is a tightly focused but stationary stream of electrons which can burn a hole in the phosphor while the filament is cooling off and the high voltage is discharging.
It almost always occurs right in the center of the screen but with some static magnetic fields around it can be elsewhere.
Well designed boxes automatically turn the intensity way down before turning off the raster but there are capacitors involved in that circuitry. We al know about those around here.
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