Video Card Problems/protecting the monitor when computer is "on"
We have a computer lab where I live with 10 stations all running windows 7. There are 10 different monitor makes and models. To use the computer, residents login to a particular user account. One is expected to log-out when finished.
One of our residents is constantly turning the monitor "off" after logging out. I am of the opinion this is not necessary. He insists it is important to not damage the monitor. I think it is not important because all that shows after logging out of a user account in windows 7 is a benign image of the user accounts that are set up on the computer.
Would you please speak to the issue of whether one needs to turn off the power to the monitor for safety reasons when the user has logged out...... ?
Firstly I'm going to say that it depends on the type of monitor you're using here - if you're using a CRT display, your resident is absolutely right; if you're using an LCD display, neither of you is wrong.
With a CRT display, the "benign image" being displayed long-term is a very bad idea - as it will lead to burn-in (you'll actually burn that image into the display face); here's more information on the "why" behind it: http://en.wikipedia.org/wiki/Screen_burn-in
This is why older computers preferenced "screen-savers" before more modern power control options were developed (very new CRTs will be able to receive a command code from the host PC to turn themselves off, which is much more power friendly than animating a screen-saver).
With LCDs, burn-in is incredibly rare ("image persistence"), and can be remedied by simply having the display draw different content for a while (generally about the same amount of time as the "burned in" image was drawn) - it isn't something that users will generally encounter in normal operation, and there's no real risk to this type of display to sit on with the same image for hours on end. However, LCDs rely on a backlight in order to function, and this is often a CCFL array that has a relatively short lifespan (usually they're quoted at between 30,000 to 50,000 hours, which is a lifetime if you're only using the display a few hours a day); so running them 24x7 will shorten their overall life cycle (instead of replacing them every 10 years or so, you may be replacing them every 3 years).
My personal inclination is to turn off monitors when not in use (of any type), partly because I'm old enough to remember CRTs and burn-in, and partly because no matter how efficient the display is, it still wastes electricity to idle them "on" when nobody is using the computer (which means a higher electric bill and a warmer room (as they do put out some heat)). The concern over life-cycle on an LCD is important, but it's more of a "long term" problem (in that you're taking years off of the display, but you won't kill it overnight).