I was just reading the SDMB and my monitor just did a strange thing it’s not done before…
There was a sound, a little like a (quiet) spark, from somewhere near the back, the image dimmed and shrunk by …oh, around 10%. The image then brightened and resized to normal over about two or three seconds.
Any ideas what caused this? I have checked the power lead and it’s in and secure. I am running off a UPS and there was no indication of a power fluctuation. Is my monitor about to die, do you think?
(Info: It’s a Mitsubishi Diamond Pro 900u - 19" CRT)
Hmm, thanks for the idea… but I don’t think so. The degaussing effect is different, and as far as I know, has to be manually instigated. (I just did it, yep, definitely different).
In a degauss the image shakes but does not shrink or dim significantly, and the noise is louder and resonates more… this was a sharp sparky kind of sound.
No definitive answer here, but I have had this happen to me at work and at home on occasion. Both monitors have continued to work great. I just chalked to some quirk of the monitor that reacts to fluxuations in the AC current.
Again, I know this doesn’t answer your question, but it might belay some fear of harm to your monitor.
There was probably a momentary electric arc inside the set. Could be in dozen of places from the CRT HV anode, in or around the flyback transform, on the neck of the CRT, etc. Since none of the preceding probably makes any sense to you and even unplugged CRTs can be lethal, you shouldn’t take the cover off and try to DIY.
If you know someone with Real Experience in electronics repair, maybe they can do a cleaning for you. Excess dust can be a problem. Anything more serious than that would require real money to fix and is probably not worth it.
ftg : Thanks… I have some electrical expertise, and certainly enough to know not to attempt a DIY repair of a CRT screen. Your answer was the sort of thing I was looking for, I am grateful.
Can dust really cause such arcing? I am surprised, although I know there are very high voltages in the monitor.