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Hardware Conundrum - Can you help?

Community Veteran
Posts: 1,112
Registered: 30-07-2007

Hardware Conundrum - Can you help?

I have a hardware issue that I can’t seem to pin down so I thought I might pick some forum brains for suggestions.
I am currently putting together a Windows 7 PC from various spares that I have. However I am getting some sporadic screen corruption but can’t identify what is causing it.
The only place I have seen the corruption is occasionally on the backdrop, altering the backdrop often makes it disappear but then changing it again might bring it back, the position of corrupt elements also changes. There appear to be no other problems, but I would like to get to the bottom of it (picture of corruption attached to post).
What I have checked so far:
I have tried two video cards. This makes no difference.
I have installed the latest Windows 7 Video Driver. This makes no difference
I have tried using both single and dual memory sticks in all position combinations. This makes no difference.
Ram has passed several hours without problem under memtest in all configurations.
I have fully reformatted the drive and reinstalled Windows 7. This makes no difference.
The drive has passed a gruelling session on Spinrite, so appears to be good.
I just can’t work this one out. I would have thought that any serious problem would have stopped the correct installation and running of the OS.
Anyone have any ideas of what to check / try next?
20 REPLIES
Community Veteran
Posts: 38,460
Thanks: 1,027
Fixes: 62
Registered: 15-06-2007

Re: Hardware Conundrum - Can you help?

Have you tried disabling the Aero effect
Community Veteran
Posts: 1,112
Registered: 30-07-2007

Re: Hardware Conundrum - Can you help?

Hi Jim
I set up two themes with transparency disabled, initially the backdrop was correct but swapping between the two a couple of times made it reappear. Good suggestion though!
Cheers
PEter
Community Veteran
Posts: 6,111
Thanks: 1
Registered: 05-04-2007

Re: Hardware Conundrum - Can you help?

Is your image a simple screenshot taken on the computer, or an image captured by an elaborate method like using a video input device on a second computer to record the graphic output of the problematic PC? If the former then that tells us something interesting: that the graphics corruption is happening at a 'deep' enough level for the operating system to record it, and not simply in the translation to a visible on-screen image provided by the GPU. I can therefore only surmise that it's a very bizarre bug in Windows. Huh
Community Veteran
Posts: 1,574
Thanks: 3
Registered: 13-04-2007

Re: Hardware Conundrum - Can you help?

Try changing the refresh rate for the monitor which can be anything from 60 to 85
Community Veteran
Posts: 1,112
Registered: 30-07-2007

Re: Hardware Conundrum - Can you help?

The backdrop is the default Windows 7 Wallpaper installed with the OS.
The problem persists at all refresh rates. I also lovered the colour depth and it made no difference.
I just placed a picture file on the desktop and opening and closing it a dozen times about 40% of the time the gallery viewer shows corruption, so it isn't just on the backdrop.
Later: I just ran the OS demo pictures as a full screen slide show and they are perfect, however opening them individually in a window the corrupt sometimes.
I just noticed that the corruption on that picture isn't totally random. Can you see it is actually following some of the light ray and bright points in the image.
MrC
Grafter
Posts: 523
Thanks: 2
Registered: 17-07-2008

Re: Hardware Conundrum - Can you help?

Strange Smiley
Quote from: God
I have tried two video cards. This makes no difference.

Some thoughts...
Are you using multiple displays? There are some reports of display corruption when using >1 physical display.
Is the graphics driver the latest Windows 7 version from the card manufacturer(s)?
Are both video cards of the same type - IOW do they use the same driver? If so can you blag a card of a different make?
Mike
Community Veteran
Posts: 38,460
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Fixes: 62
Registered: 15-06-2007

Re: Hardware Conundrum - Can you help?

Can you try knocking the graphics acceleration back a notch or two
Community Veteran
Posts: 1,112
Registered: 30-07-2007

Re: Hardware Conundrum - Can you help?

Single display, yesterdays version of the Win 7 driver, same issue through either video port. Yes they are both 800 (different models) series nvidia based cards. No access to an ATI unfortunately.
Reducing Acceleration doesn’t seem to help. I am starting to wonder if could be a faulty CPU perhaps some of the multi media instructions are shot? Although it runs video files ok.
MrC
Grafter
Posts: 523
Thanks: 2
Registered: 17-07-2008

Re: Hardware Conundrum - Can you help?

There are a few inconclusive tales of display corruption on nVidia hardware around. Do you have a friendly neighbour with an ATI board you can borrow in exchange for a few beer tokens?
Mike
Community Veteran
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Registered: 02-02-2008

Re: Hardware Conundrum - Can you help?

Are you using DVI or VGA connection to the monitor? Try the other one if at all possible, via an adapter as appropriate.
Community Veteran
Posts: 1,112
Registered: 30-07-2007

Re: Hardware Conundrum - Can you help?

Hi HP
Already tried both ports (see my last post), the problem is still there.
Cheers
Peter
VileReynard
Seasoned Pro
Posts: 10,823
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Registered: 01-09-2007

Re: Hardware Conundrum - Can you help?

Have you tried the same image on a different OS?  Smiley
Or a different image on the same OS?
Personally, I've had occasional trouble with ATi - but never with nvidia.
Are you using the latest video driver - it could be worth trying a previous release of your video driver.
Sometimes you get hurt sliding down the bleeding edge.

StickyMick
Grafter
Posts: 325
Registered: 29-11-2008

Re: Hardware Conundrum - Can you help?

You haven't got Anti-Aliasing set for the desktop have you, that can have some strange side effects.
nVidia have been botching the drivers a lot lately. Issues ranging from no control over digital vibrancy to just not working at all (the case for the latest drivers for my 7300GT). They also seem to have a desire for messing about with the folder structure in the install routine, which makes the use of Driver Cleaner a must.
Community Veteran
Posts: 6,735
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Registered: 02-02-2008

Re: Hardware Conundrum - Can you help?

Quote from: God
Already tried both ports (see my last post),

Yes, but is one DVI and the other VGA?
A lot of cards have 2 DVI ports that also support VGA via an adapter. There is a difference, the cards usually auto-sense what is connected.
It's not that long since I saw a PC where one type of connection worked fine the other actually blue-screened! Same port.  Shocked