Fires of Heaven Guild Message Board - View Single Post

Haldin Darconis · 03-17-2005, 02:25 PM

Generally speaking, LCDs are less likely to "shimmer" due to electrical problems or magnetic fields. There are several reasons for this.

First, the pixels on an LCD screen tend to stay illuminated longer than the phosphors on a CRT. This means a very brief fluctuation that can be seen on a CRT might be unnoticable on an LCD, even though the fluctuation still would technically be there.

The bigger reason for this is, as you said, because "they don't have nearly as much to do with charged particles and magnetic fields and electrons like a CRT monitor does." A CRT has an electron gun that sends electrons from the back of the tube to the front. This causes phosphors on the front of the screen to become excited and display the image. It's easy to see how minor electrical fluctuations could throw this system off and cause problems, especially since this electron beam is guided by an electromagic (usually called a "steering coil") within the monitor. However, LCDs basically work like stained glass. They have a light source behind the screen that shines through a screen that consists of tens of thousands of little cells. These cells contain liquid crystals that, when a charge is applied, only allow certain colors of light to pass through.

LCDs are basically hard-wired systems where everything is locked in place. CRTs have to make "leaps of faith" from cathode to anode to the screen.

You said you hooked up another monitor and it was fine, but then when you actually replaced the monitor the problem was back. It may be a problem with the computer. I would suggest, if possible, setting up an entirely different computer and monitor in the office to see if the problem shows up. If the issue doesn't occur with a new system, then the problem most likely is either the monitor (doubtful, since you've tested a few) or is coming from the computer iteself. My first guesses would be either power supply or video card if this is the case. However, if it persists with a new setup, the problem is almost definitely electrical in the office.

I've been in similar situations. For example, I had an area of a building with less-than-reliable electricity where monitors would flicker and shimmer. They wouldn't fix the electrical problems, but one solution (besides an LCD) was to get a Line Conditioner. These basically force the incoming electricity to behave nicely. This can also extend the life of electronics hooked up to this questionable power. Tripplite makes some basic ones that seem to do a pretty good job.
( http://tripplite.com/products/produc...productID=2010 )

Finally, this can be caused by electrical noise in the circuit. Sometimes another device (I've found laser printers can often be the culprit) plugged into the same surge protector or even just another outlet on the same circuit can pollute the electricity and cause some sensitive equipment to behave oddly, including shimmering on a monitor.

03-17-2005, 02:25 PM	#2 (permalink)
Haldin Darconis Me. Join Date: Jun 2003 Posts: 140 +0 Internets	Generally speaking, LCDs are less likely to "shimmer" due to electrical problems or magnetic fields. There are several reasons for this. First, the pixels on an LCD screen tend to stay illuminated longer than the phosphors on a CRT. This means a very brief fluctuation that can be seen on a CRT might be unnoticable on an LCD, even though the fluctuation still would technically be there. The bigger reason for this is, as you said, because "they don't have nearly as much to do with charged particles and magnetic fields and electrons like a CRT monitor does." A CRT has an electron gun that sends electrons from the back of the tube to the front. This causes phosphors on the front of the screen to become excited and display the image. It's easy to see how minor electrical fluctuations could throw this system off and cause problems, especially since this electron beam is guided by an electromagic (usually called a "steering coil") within the monitor. However, LCDs basically work like stained glass. They have a light source behind the screen that shines through a screen that consists of tens of thousands of little cells. These cells contain liquid crystals that, when a charge is applied, only allow certain colors of light to pass through. LCDs are basically hard-wired systems where everything is locked in place. CRTs have to make "leaps of faith" from cathode to anode to the screen. You said you hooked up another monitor and it was fine, but then when you actually replaced the monitor the problem was back. It may be a problem with the computer. I would suggest, if possible, setting up an entirely different computer and monitor in the office to see if the problem shows up. If the issue doesn't occur with a new system, then the problem most likely is either the monitor (doubtful, since you've tested a few) or is coming from the computer iteself. My first guesses would be either power supply or video card if this is the case. However, if it persists with a new setup, the problem is almost definitely electrical in the office. I've been in similar situations. For example, I had an area of a building with less-than-reliable electricity where monitors would flicker and shimmer. They wouldn't fix the electrical problems, but one solution (besides an LCD) was to get a Line Conditioner. These basically force the incoming electricity to behave nicely. This can also extend the life of electronics hooked up to this questionable power. Tripplite makes some basic ones that seem to do a pretty good job. ( http://tripplite.com/products/produc...productID=2010 ) Finally, this can be caused by electrical noise in the circuit. Sometimes another device (I've found laser printers can often be the culprit) plugged into the same surge protector or even just another outlet on the same circuit can pollute the electricity and cause some sensitive equipment to behave oddly, including shimmering on a monitor.