Annoying green pixels

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Joined
25 Nov 2006
Posts
15
Location
Aarhus, Denmark
Hi all

I have a problem with my computer, see signature for specs, which started out as a minor irritant, and has now evolved into a sleepwrecking issue. I have tried to search the web to find people with the same problem, but to no avail. I hope that somebody, with better hardware knowledge than myself, can figure out what the problem is.

Description of the problem:

I have green pixels on the screen organized approximately on a horizontal line. They are green on blue, black, red, and green backgrounds.
On white backgrounds they usually do not appear. When they do they are purple, not green.

The position of the pixels are constant, although they vary slowly in number, turning on and off (in 3D they oscillate more wildly).

Lowering the resolution pushes the pixels down.

Moving or scrolling windows leave green trails, never purple.
Purple pixels do move with the window but the trail is green (on black text for example)

When hardware acceleration is turned off (Properties->Troubleshooting),
pixels still appear as before but they leave no trail in windows.

Green pixels also appear during bootup, before XP is loaded,
but here they are entirely on a horizontal line.

The problem evolved slowly during the first weeks after I received
the computer and the GPU (early september).
After about 4-7 weeks it peeked, and has been the same since.
On occasion it flashes colours during bootup, but not in XP.

I have taken some screenshots (all except Pic7 are shot in 1152x864)

The bare green pixel problem:
Pic1.

Moving a window around leaves green trails, on blue background:
Pic2.

Moving notepad around leaves no trails on white background,
only the black text is coloured:
Pic3.

The view from EVE. (Here the pixels are blinking):
Pic4.

Mixed green and purple pixels on a checkboard background:
Pic5.

The pixels in 1024x768 (In 800x600 the green pixels do not show):
Pic7.

With catalyst drivers and CCC uninstalled. Pixels organized on a line.
(During bootup the green pixels are similarly organized.):
Pic13.

The entire PC was bought from a danish etailer, except for the
GPU which is bought from overclockers. The entire PC has been tested by the danish etailer, and the GPU has been tested by overclockers.
The danish etailer presumes the fault lies with the graphics card,
and overclockers says the graphic card has no faults.

The PC has otherwise absolutely no problems. It runs everything without breaking a sweat, and I get no 3D artifacts. It is entirely a cosmetic problem, and amounts to exactly what can be gleaned from the screenshots.

Does anybody out there have a clue as to what might be the cause of the problem?
 
I think its more of a monitor fault than the gpu but you might want to try downloading the newest driver or the last known stable driver version.
 
Well, Ive tried on two different monitors, with two cables. Besides, there are the screenshots, which kinda rules out a monitor issue I would think :cool:
 
Lolcb said:
I think its more of a monitor fault than the gpu but you might want to try downloading the newest driver or the last known stable driver version.

If it was a monitor fault then surely the pixels wouldn't show up in screenshots?
 
As for drivers, i tried the following. Catalyst 6.8, 6.9, 6.11, and
on a fresh XP install without any drivers (expect for the ones coming with XP). I am getting a solid score of 5849 in 3DMark06 with 6.11.
 
i have a similar looking problem, i get hundreds of these horizontal lines of green/purple pixels but only appear on videos, there is a bit of distortion on my pointer icon but other than that windows/games look normal.

I assume that my graphics card is on the way out for 2 reasons:
1) Artifacts can bee seen before windows loads, so im thinking that it isnt a software issue.
2) My troubles started around the same time that my gfx card cooler stopped working, its been replaced now but i think i'v prolly overheated and damaged it.
 
That sounds bizarre. I dont have any temp issues with GPU nor board nor CPU. I just played Oblivion the entire day, and the work has cut down the number of green pixels to a single one right now.
 
Well if it's not the monitor (due to the screenshots) then it must be the gfx card. Most probably a memory problem. Could you get a really cheap replacement (still ATI so the drivers don't need to change) and test that out? If still occuring then it's clearly the card.
 
In fact the company I bought everything from ecept the GPU did just that, and the problem went away. They plugged in a X1950XTX.
The problem returned when my card was put back in.

However, overclockers tested the card and found no problems!
This is what is so mindboggling about it.
 
Then imho OcUK didn't test it properly or the problem didn't occur when they did. It clearly seems to be the gfx card. I'd give them another ring.
 
I am communicating with them over the webnote system, but so far
they are sticking to their first conclusion.

Does the screen always reside in the same part of the GPU RAM?
If it does then it could be defective RAM in the GPU
That would also explain why turning of hardware acceleration stops the trailing pixels (no blitting the screen around).

Also: Three different RAM sticks has been through the machine and I ran memtest86, so thats not where the problem is.
 
Ask what resolution and colour depth they tested at. Ask how they tested it. Do these test reproduce it? If not then ask them to run it at your color depth, etc. If all else fails then can you put it in another machine to test it conclusively?

If it absolutely definitely is the card (ie it occurs when the card is in another machine) then you have a right to return it. Not talking specifically about OcUK here because they get a bit funny about shop talk on the forums but as a general rule for any retailer:

1) You may get more joy from the manufacturer (ATI).

2) But strictly speaking you have a contract with the retailer not the manufacturer.

3) If the product is still under warranty then you could approach either the retailer or the manufacturer (but as stated above your contract is with the retailer in the event of further action).

4) If you bought with a credit cardand the total cost was over £100 then the credit card company is jointly liable under the consumer credit act (again assuming if stil under warranty).

5) Or small claims court.

But obviously explore all avenues with the retailer first :) Try to establish how it was tested and whether that would reproduce the problem. Not much point sending it back again if they just test it the same way and don't find any problem. For example they may run some kind of diagnostic software and not actually look at the screen.

Incidentally I had an old Matrox gfx card which had verticle lines down it. That was faulty gfx card RAM.
 
This morning I informed overclockers of this forum thread, so they could take a look at the pictures. The webnote system unfortunately does not allow the submission of pictures.
They quite rapidly replied and now agree that it points to the gfx card. They gave me a new RMA number :) . In general I think they have been quite snap with their replies, althouh i may not always have agreed with the thrust of their argument ;)

I will make a CD with bitmap pictures of what the problem looks like and send it with the card, in order to avoid any confusion as to what the problem is. Something I should have done the first time I send the card back.
Describing the symptoms concisely in text can be quite hard, which may be what went wrong before. I should probably try to get pictures when the problem is the least noticable. The ones posted here are the most severe cases.

Thanks for your help!
 
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