LCD TV - white glow along the edges - what is it?

madkingsoup · 02-12-2005, 15:40

We've got an LG LCD TV. Over the past couple of months, we've noticed that all around the edge of the screen a white glow is creeping into the picture. It's as if someone is shining a light in from each side, or fixing strong magnets along each edge (which we don't have, of course).

Is this a common LCD TV problem, or what? LG have given us the runaround, trying to fob us off with all manner of excuses, even going as far as saying that it's a normal problem with all LCD TVs, which I find unlikely.

However, I may be wrong. I know nothing about LCD screens, so does anyone know anything about this sort of thing?

It's an LG RZ-20LA70 (20").

Dino · 02-12-2005, 16:26

LCD's are backlit, there is usually a metal reflector behind the LCD screen that reflects light from a flourescent light (or lights) mounted on one side (or sides) of the screen. The light is the width (height) of the screen. The LCD panel then masks the white light to get the picture, so black = mask all light, a red screen = mask all green and blue light.

LCD TV's are not affected by magnets; they are a solid-state technology. It sounds like that light from the reflector is somehow visible around the edges of the screen; maybe it's not being masked correctly. It's quite possible that the light has always been there but you have just noticed it.

I would personally say that it is not acceptable; I've got half a dozen LCD screens around me at the moment from various manufacturers from 15" up to around 42" and none of them exhibit this problem.

My Dell Latitude D810 sometimes does it first thing in the morning if it's been brought in from the cold, although it's only for a second or two and at the bottom; probably something to do with LCD's and extreme cold; probably seeing the backlight switch on before the LCD has switched to black, hence blocking all the light. It doesn't do it after subsequent switch-ons after it has warmed up.

Toshiba · 02-12-2005, 18:19

What does the opposite mean - when the edges of an LCD become slightly darker than the rest, especially in the bottom corners?

Dino · 02-12-2005, 18:51

Quote:

Originally Posted by Toshiba

What does the opposite mean - when the edges of an LCD become slightly darker than the rest, especially in the bottom corners?

Either a poor reflector / backlight combination or tunnel vision / cataracts.

madkingsoup · 02-12-2005, 20:09

Thanks, Dino. Would you believe the LG authorised service guy actually suggested that it could be magnets - aren't they a shower!Well it definitely sounds like a fault then, and we won't be fobbed off when we call them back!

Dino · 02-12-2005, 20:46

Quote:

Originally Posted by madkingsoup

Thanks, Dino. Would you believe the LG authorised service guy actually suggested that it could be magnets - aren't they a shower!Well it definitely sounds like a fault then, and we won't be fobbed off when we call them back!

Magnets. That's poor. Give 'em hell, tiger!

02-12-2005, 15:40	#1
madkingsoup Forum Member Join Date: May 2004 Location: Slough Posts: 119	LCD TV - white glow along the edges - what is it? We've got an LG LCD TV. Over the past couple of months, we've noticed that all around the edge of the screen a white glow is creeping into the picture. It's as if someone is shining a light in from each side, or fixing strong magnets along each edge (which we don't have, of course). Is this a common LCD TV problem, or what? LG have given us the runaround, trying to fob us off with all manner of excuses, even going as far as saying that it's a normal problem with all LCD TVs, which I find unlikely. However, I may be wrong. I know nothing about LCD screens, so does anyone know anything about this sort of thing? It's an LG RZ-20LA70 (20").

02-12-2005, 16:26	#2
Dino Forum Member Join Date: Nov 2001 Location: South Manchester Posts: 1,990	LCD's are backlit, there is usually a metal reflector behind the LCD screen that reflects light from a flourescent light (or lights) mounted on one side (or sides) of the screen. The light is the width (height) of the screen. The LCD panel then masks the white light to get the picture, so black = mask all light, a red screen = mask all green and blue light. LCD TV's are not affected by magnets; they are a solid-state technology. It sounds like that light from the reflector is somehow visible around the edges of the screen; maybe it's not being masked correctly. It's quite possible that the light has always been there but you have just noticed it. I would personally say that it is not acceptable; I've got half a dozen LCD screens around me at the moment from various manufacturers from 15" up to around 42" and none of them exhibit this problem. My Dell Latitude D810 sometimes does it first thing in the morning if it's been brought in from the cold, although it's only for a second or two and at the bottom; probably something to do with LCD's and extreme cold; probably seeing the backlight switch on before the LCD has switched to black, hence blocking all the light. It doesn't do it after subsequent switch-ons after it has warmed up.

02-12-2005, 18:19	#3
Toshiba Forum Member Join Date: May 2005 Location: London Posts: 620	What does the opposite mean - when the edges of an LCD become slightly darker than the rest, especially in the bottom corners?

02-12-2005, 18:51	#4
Dino Forum Member Join Date: Nov 2001 Location: South Manchester Posts: 1,990	Quote: Originally Posted by Toshiba What does the opposite mean - when the edges of an LCD become slightly darker than the rest, especially in the bottom corners? Either a poor reflector / backlight combination or tunnel vision / cataracts.

02-12-2005, 20:09	#5
madkingsoup Forum Member Join Date: May 2004 Location: Slough Posts: 119	Thanks, Dino. Would you believe the LG authorised service guy actually suggested that it could be magnets - aren't they a shower!Well it definitely sounds like a fault then, and we won't be fobbed off when we call them back!

02-12-2005, 20:46	#6
Dino Forum Member Join Date: Nov 2001 Location: South Manchester Posts: 1,990	Quote: Originally Posted by madkingsoup Thanks, Dino. Would you believe the LG authorised service guy actually suggested that it could be magnets - aren't they a shower!Well it definitely sounds like a fault then, and we won't be fobbed off when we call them back! Magnets. That's poor. Give 'em hell, tiger!

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LCD TV - white glow along the edges - what is it?