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#153578 - 06/04/2003 20:39 3 year old LCD - dark horizontal streaks
Ezekiel
pooh-bah

Registered: 25/08/2000
Posts: 2413
Loc: NH USA
I've just spent the better part of 2 hours fruitlessly googling, perhaps someone here can help (please!)

My wife's machine is a 3 year old Dell with a Dell/Philips 15" LCD monitor. Recently it has developed horizontal dark 'shadows' that trace from left to right, trailing darker areas of the screen (think title bar of windows). It does not matter the refresh rate or resolution (even down to 60 Hz 800x600) and wiggling wires does not seem to effect it. The connection is analog. Is this monitor giving up the ghost? I'm stumped.

-Zeke
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#153579 - 06/04/2003 22:35 Re: 3 year old LCD - dark horizontal streaks [Re: Ezekiel]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
Have you tried the monitor on another computer or another monitor on the computer?

The symptoms you describe sound like a problem a friend of mine and I both had separately when our video cards went south, and not a monitor problem at all.
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#153580 - 07/04/2003 03:35 Re: 3 year old LCD - dark horizontal streaks [Re: Ezekiel]
BartDG
carpal tunnel

Registered: 20/05/2001
Posts: 2616
Loc: Bruges, Belgium
That to me sounds like the backlit panel of that monitor is dieing. Which isn't all that uncommon with a 3 year old LCD monitor. (especially the previous generations)

The backlit panel in an LCD screen is usually one of the first things to go in an LCD panel. (that and dead pixels of course).
I'm sorry, but I doubt you will be able to solve this without sending it in for repair.
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#153581 - 07/04/2003 05:28 Re: 3 year old LCD - dark horizontal streaks [Re: wfaulk]
Ezekiel
pooh-bah

Registered: 25/08/2000
Posts: 2413
Loc: NH USA
Bitt - I'll give that a try tonight. I'd much rather replace a vid card than a monitor.

Archeon - The overall brightness is still OK, just very streaky. I figured if the backlight was going, it would simply get darker and darker, right?

-Zeke
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#153582 - 07/04/2003 07:02 Re: 3 year old LCD - dark horizontal streaks [Re: Ezekiel]
BartDG
carpal tunnel

Registered: 20/05/2001
Posts: 2616
Loc: Bruges, Belgium
Normally I's say yes to that, but it is also possible that only parts of the screen become dimmer.
I believe (I'm not sure about this, so somebody correct me if I'm wrong), that the backlight of a TFT monitor is also built up in segments. So I think that it's possible that if one specific segment dies, only that part becomes dimmer.
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#153583 - 07/04/2003 07:37 Re: 3 year old LCD - dark horizontal streaks [Re: BartDG]
AndrewT
old hand

Registered: 16/02/2002
Posts: 867
Loc: Oxford, UK
I believe (I'm not sure about this, so somebody correct me if I'm wrong), that the backlight of a TFT monitor is also built up in segments.

I've changed laptop backlights in the past and they have always been continuous tubes running along the top and bottom (or up the sides for that matter) of the display with a single diffuser in between. If a single tube fails then the display gets progressively darker from top to bottom (or bottom to top!) and if both fail (usually a circuit fault) then you can't make out any on-screen display at all. When I read the original post here it didn't strike me that the backlight was the culprit but I could be wrong.

Changing the FL tubes is the extent of my experience with TFTs but I've always believed that the active drive electronics are segmented.
Assuming that changing the display adapter doesn't fix this I'd bet on the electronics. The electronics can be fixed by specialist firms with the proper equipment but I don't know if that's economically viable.

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#153584 - 07/04/2003 07:41 Re: 3 year old LCD - dark horizontal streaks [Re: AndrewT]
BartDG
carpal tunnel

Registered: 20/05/2001
Posts: 2616
Loc: Bruges, Belgium
I've changed laptop backlights in the past and they have always been continuous tubes running along the top and bottom

Ah. I stand corrected then!
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#153585 - 07/04/2003 09:38 Re: 3 year old LCD - dark horizontal streaks [Re: AndrewT]
Ezekiel
pooh-bah

Registered: 25/08/2000
Posts: 2413
Loc: NH USA
Rue,
Thanks for the explanation. I don't think it's the backlight then, from what you describe (hooray!). The dark blurs will move with darker areas on the screen. For example, if I move a window, the dark blur next to its title bar (usually dark blue on this machine) travels with it, like a smear of wet ink. Icons on the desktop will have smaller blurs, depending on how bright (or dark) they are. The blurs are definitely screen-content connected, so I think Bitt may be on the right track. The only other component I can think of is the cable, and swapping computers & cables should let me find out if that's the problem (I assume the cable is removable, we'll see!)

-Zeke
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#153586 - 07/04/2003 18:59 Re: 3 year old LCD - dark horizontal streaks [Re: wfaulk]
Ezekiel
pooh-bah

Registered: 25/08/2000
Posts: 2413
Loc: NH USA
We have a winner. The monitor worked 100% on my machine. Now, which video card to buy for an old PIII 600? I suppose just about anything today will beat the TNT2 Ultra that is going south. Suggestions? I do use this machine for network QIII (against a PIII 850 w/ same vidcard, it's pretty fair).

-Zeke
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#153587 - 07/04/2003 19:21 Re: 3 year old LCD - dark horizontal streaks [Re: Ezekiel]
pca
old hand

Registered: 20/07/1999
Posts: 1102
Loc: UK
It sounds like a grounding fault. If, as your later reply indicates, swapping out the video card fixes it, the connector on the card is most probably faulty. I've seen the same problem on CRTs as well, usually caused by a bad cable although once or twice it was the VGA card connector. The repeated stresses of connecting and disconnecting the plug, or sometimes just the weight of the cable, breaks one or more joints inside the connector or where it joins the PCB, and you end up with a floating ground. The symptoms are exactly as you describe.

pca
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#153588 - 07/04/2003 20:13 Re: 3 year old LCD - dark horizontal streaks [Re: Ezekiel]
wfaulk
carpal tunnel

Registered: 25/12/2000
Posts: 16706
Loc: Raleigh, NC US
TNT2 Ultra
Interestingly, that's the exact same GPU on the card I had that went south. My friend's was a 1st-gen GeForce. The manufacturer claimed that it was a memory problem, but what do I know?
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#153589 - 07/04/2003 20:29 Re: 3 year old LCD - dark horizontal streaks [Re: pca]
Ezekiel
pooh-bah

Registered: 25/08/2000
Posts: 2413
Loc: NH USA
Bad cable was my first thought, but it failed the wiggle test, which usually showed some response on the CRT's I'd seen this type of behavior on. Luckily the display has a digital connection so if the VGA cable (integrated) is shot, I'll probably be using the digital cnx anyhow. I assume all the newer cards have a digital out?

-Zeke
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#153590 - 08/04/2003 02:06 Re: 3 year old LCD - dark horizontal streaks [Re: Ezekiel]
BartDG
carpal tunnel

Registered: 20/05/2001
Posts: 2616
Loc: Bruges, Belgium
Just make sure when you buy a new video card that you buy one that is suposed to run in a P3.
You might think that is silly, but the AGP specs have changed since the TNT2. The cards you buy now require more power and will not work in an old motherboard that is not capable of providing the juice it needs. (voltage went up from 3.3 to 5v I believe).
That AGP upgrade didn't even seem to be enough for today's cream of the crop cards (ATI 9700 & nVidia Gforce FX), 'cause these cards also feature a molex connector on them because the AGP slot isn't able to provide enough power to it - again.
That should be solved with the new forthcoming PCIexpress technology.

Some motherboards can be damaged when the wrong type of AGP card is inserted, and they carry a warning sticker.
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#153591 - 08/04/2003 05:45 Re: 3 year old LCD - dark horizontal streaks [Re: BartDG]
Ezekiel
pooh-bah

Registered: 25/08/2000
Posts: 2413
Loc: NH USA
Thanks, I didn't know that. I'll be sure to check. Fried Mobo isn't a dish I care for.

-Zeke
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#153592 - 08/04/2003 06:43 Re: 3 year old LCD - dark horizontal streaks [Re: Ezekiel]
JBjorgen
carpal tunnel

Registered: 19/01/2002
Posts: 3583
Loc: Columbus, OH
I love my All-in-Wonder Radeon. I'll nominate it for your next card.
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#153593 - 08/04/2003 07:01 Re: 3 year old LCD - dark horizontal streaks [Re: BartDG]
tman
carpal tunnel

Registered: 24/12/2001
Posts: 5528
It's still not as crazy as the 3dfx Voodoo 5 6000 which needed it's own external PSU
I don't think it was ever released to the public. Quantum3D may have sold it in one of their graphics workstations though.

- Trevor

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#153594 - 08/04/2003 12:16 Re: 3 year old LCD - dark horizontal streaks [Re: tman]
BartDG
carpal tunnel

Registered: 20/05/2001
Posts: 2616
Loc: Bruges, Belgium
Yeah, I remember those! But only from photos. Never seen one IRL. You're probably right : it probably never was release to the public.
I think 3DFX went TU before they were able to release it. Not that I think it was a viable product anyway.
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#153595 - 08/04/2003 18:08 Re: 3 year old LCD - dark horizontal streaks [Re: JBjorgen]
Ezekiel
pooh-bah

Registered: 25/08/2000
Posts: 2413
Loc: NH USA
Well, I couldn't bring myself to spend for the AIW, but I got a Radeon 9000 64MB. Should have it in a week or so. I figured it wouldn't stress the system _too_ much. Specs said it was Ok for PIII's, so here's hoping!

-Zeke
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#153596 - 16/04/2003 20:12 Re: 3 year old LCD - dark horizontal streaks [Re: Ezekiel]
Ezekiel
pooh-bah

Registered: 25/08/2000
Posts: 2413
Loc: NH USA
Conclusion: Radeon 9000 fixed the problem & sped up QIII to boot. Thank you all!

-Zeke
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