Long pauses will burn DVDs

[blinkingblythe]

I've seen some very nasty burn in on monochrome CRT computer monitors from the 1980s. Looked like a photographic negative that was exposed several times with text overlaying other text in a jumble. I've also seen a 1950s tv set with a very nasty burn about 1 inch by 1 inch in the center of the screen. My theory is is that the overvoltage protection circuts failed thus causing the CRT's electron gun to put out far more power than it was supposed to. The deflection coils (which draws the scan lines and also moves the beam up and down the screen suffered a voltage drop due to the gun taking so much power thus drawing the picture in only a small area (in center because that is where the beam defaults to when the coils are not active). I imagine the set was also putting out some dangerous x-rays as well, the reason for the overrvoltage protection circut to begin with.

[blinkingblythe]

Originally Posted by AsForMe

I just popped out a CD-R from my secondary computer, which I don't bother with much. Imagine my surprise when I noticed a gigantic hole burned right through the material. Not the plastic mind you, although it heated up so much that it cracked.

I have no idea how it happened, if the disc got stuck in there or what. The conspiratorial side of me thinks there might be a really malicious virus that took control of the drive! But I have no evidence. Just the hole.

you can check out the picture on my facebook page at:

http://www.facebook.com/photo.php?pi...7&id=640407949

-Ben

Sounds like the write laser engaged while the disc was idle (spun down). Failing virus, you probaly should replace the drive.

[Troberg]

Originally Posted by blinkingblythe

I've also seen a 1950s tv set with a very nasty burn about 1 inch by 1 inch in the center of the screen. My theory is is that the overvoltage protection circuts failed thus causing the CRT's electron gun to put out far more power than it was supposed to. The deflection coils (which draws the scan lines and also moves the beam up and down the screen suffered a voltage drop due to the gun taking so much power thus drawing the picture in only a small area (in center because that is where the beam defaults to when the coils are not active).

Well, if the electron beam sweep stops, you'll get a burn in. Basically, instead of getting hit by the beam about one millionth of the time, the spot will be constantly hit. However, that will not happen on a working screen under normal operation. On oscilloscopes (old CRT design, today, most are just a computer with some analyzing software and input hardware), however, it can certainly happen.

I imagine the set was also putting out some dangerous x-rays as well, the reason for the overrvoltage protection circut to begin with.

X-rays? That sounds a bit excessive.