What is causing this weird screen breakup?

[Matt00011]

Hiya guys long time no speak.

PC has been running great for near on 2 years now, it's been excellent on the whole, however as of late I've started to get random pixel breakup on my screen shortly after it boots into Windows, other times completely randomly. I will attach a picture. It usually happends shortly after I've booted into the system and the startup items have loaded. it's more likely to happen on a cold boot, the problem usually goes away for hours after a couple of reboots and repeats of the problem. The complete screen automatically breaks up to an unrecognizable mess, and I no longer have control over the mouse either, it's a clean lock up.

http://img84.imageshack.us/img84/4441/screenlf.jpg

I've already reinstalled Windows hoping it was driver related but the problem still persists. I'm wondering if it's either the graphics card, PSU or RAM?

Looking in event viewer I'm getting Event 41, Kernal-power errors, I also have problems with the AMD fuel service which I've disabled.

System is clean, run all virus and malware scans. Should I run onboard from bootup to see if the problem still persists?

Specs:

Case COOLERMASTER ELITE 310 BLUE CASE
Processor (CPU) AMD PHENOM II X4 955 (3.20GHz/8MB CACHE/AM3) - BLACK EDITION
Motherboard ASUS® M4A78LT-M: mATX MAINBOARD, DDR3, USB 2.0, SATA 3.0Gb/s
Memory (RAM) 4GB SAMSUNG DDR3 DUAL-DDR3 1333MHz (2 X 2GB)
Graphics Card 1GB ATI RADEON™ HD 6850 PCI EXPRESS - DirectX® 11
Memory - 1st Hard Disk 1TB WD CAVIAR GREEN WD10EARS, SATA 3 Gb/s, 64MB CACHE
1st DVD/BLU-RAY Drive 24x DUAL LAYER DVD WRITER ±R/±RW/RAM
Memory Card Reader INTERNAL 52 IN 1 CARD READER (XD, MS, CF, SD, etc) + 1 x USB 2.0
PORT
Power Supply & Case Cooling 600W Quiet 80 PLUS Quad Rail PSU + 120mm Case Fan (£59)
Processor Cooling STANDARD AMD CPU COOLER

Cheers!

[baron75mk2]

can you lay your hands on another GPU to see if it still does it ? - just to eliminate the gpu

[Adli]

my dad kept having those issues on his Dell laptop, almost exactly the same image. a few weeks ago his Dell GPU died.

i would suggest testing your PC with another GPU

[Matt00011]

Cheers guys for the help! Definitely looks like the GPU then, or all indications it could be related to that.

Unfortunately I can't lay my hands on a test GPU at the moment but will keep monitoring the situation and let you know how it goes.

[deh-cheesekake]

Do you have access to an alternate set of cables from the back of your PC to your monitor, I am thinking that either the cable could be fraying inside or the connecters on either the monitor or GPU are damages, just a suggestion

[Matt00011]

Cheers for the replies guys.

I've checked the cabling this morning all seems fine, nothing appears to be damaged to my eyes. I ultimately decided to upgrade the graphics card to a Gigabyte 7850 OC edition and have installed the new card this morning. Fingers crossed no more problems. The 6850 crashed this morning before I changed to the 7850 (complete system lock up while showing a similar screen as posted in opening post, scrambled lines across the entire screen etc) shortly after a bootup when I tried to load youtube via Chrome, and this repeated again shortly after a second reboot. Hoping the video ram on the card is the cause and the new card will rectify the problems otherwise I'll be spitting feathers haha.