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To simplify for the reader, an oversimplified version of my question comes first (though perhaps it is enough).

SUPER-SHORT version

Is it possible for a power supply to be failing in such a way that it causes problems which would normally appear to be GPU related symptoms? (even though said PSU is rated for said GPU)

Fully explained problem

So, I have a kinda old (maybe closing on 5 years) windows XP system. I've been trying to repair it for awhile now cause I just didn't have the money to replace it. It's kind of been a long process, and the symptoms have evolved over time.

I first noticed problems when playing Path Of Exile, the system would freeze up (no BSOD, just frozen). No matter what I did to lower the requirements, it would just happen every once and awhile, but limited to the game. After awhile these freezes would actually dump me back into the desktop, but at the lowest resolution possible and the colors would be all distorted.

Obviously, I assumed "bad GPU" -> replace.

to shorten the rest of the story (sorry):

-The GPU has been replaced with a new Radeon R6570 1GB (not the best, but scrapping this system as soon as I can afford to)

A similar but different problem occurred (to be described shortly) which resulted in

-complete HDD reformat and windows XP reinstall (SP3) -replacing the motherboard and CPU with a used but functional pair (friend hand me down) -similarly replaced RAM

So now, there are pretty much NO remaining elements of my ORIGINAL system, except for the wireless PCI card and PSU. (Note the HDD is only 2 months old, so I don't think its corrupt). Nonetheless, a very similar problem persisted throughout each stage, even though it has been in a slightly different form since the GPU was replaced (which was replaced TWICE, by exchanging what I thought was a "faulty" first one into the store).

The problem exists outside of games, or really taxing operations. What it can best be described as is a checkerboard pattern of small, colored, somewhat transparent pixelated regions on my screen, usually blue or yellow (but always the same color at once). Occassionally, but not always, everything freezes up like this for 5-10 seconds, then the monitor goes black and comes back after a moment all systems normal (though occasionally the browser window viewport will remain forever black until restart).

Normally, this screams GPU to me... but having replaced it twice, uninstalled/reinstalled/updated the drivers 4 times, reinstalled the entire OS, even replacing the damn motherboard.... I don't see how it could be. Since the PSU is the ONLY thing I have yet to replace, before I dropped another 50$ on one I wanted to ask the brilliant minds here... could it ACTUALLY be the problem?

note my current PSU IS rated high enough to handle this GPU (450W), and no... nothing is overheating.

Thanks so very much for your help. I'm sorry this was so long. I'm just SO frustrated >_<

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Thats the main reason why I long discarded ATI from my shopping list. They have the best in terms "cost-benefit", but glitches like those you described are common in their graphic cards, specially when they start to get old. I don't think the PSU could be doing that, but seen its one of the cheapest parts of the computer you might consider buying a new one, or just borrowing one from this friend of yours. Let us know if replacing the PSU fixed the problem, this information might be valuable for others. –  Havenard Apr 11 '13 at 6:05

2 Answers 2

It seems that either your PSU is not providing a strong electrical current. in most situations, if a GPU does not have enough power to run then it will not output anything to the screen, but if it suddenly looses power during its use, then it can cause problems like the ones you are experiencing.

Now, I am not familiar with your specific GPU's electrical needs, and weather or not it requires any power connectors from the PSU or can operate just off of the Mobo, but most likely your power source is either not getting enough power from your house to produce a strong current, or somewhere within the PSU there is some sort of fault causing it not to deliver a strong current to your components.

Try plugging the computer into another electrical plug somewhere else in your house- preferably in a different room on a different circut- and see if it still gives you these errors. If you still have the same problems and they occur at the same intensity they did before, this would lead me to believe that the PSU is really the problem, and I would advise you try a different one for a bit to see what happens.

If it doesn't occur in the other room, then that narrows down the cause to being that the electrical plug you were previously hooked into is faulty- and you really should not use it if this is the case. Continued use of a faulty plug can cause fires, or damage components connected to it.

I am currently living in a house from 1962, with all original electrical circuitry. When i first moved into this house a month ago, I plugged in my iPhone to the kitchen power plug, the thing made a loud POP noise, and the battery got fried on said iPhone. One can pick up a testing device for such plugs to see if they are safe, they cost a very small amount of money at home depot or any hardware store (4-20 dollars depending on features). I'd advise that you pick up one of these and test out the plugs you were using, to see if they need replacing, so you can hopefully avoid busting your technology, like i did with my iPhone.

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Could you please format your question and insert some paragraphs :) –  nixda Oct 4 '13 at 8:13
    
hehe sure, sorry, I was writing it rather fast :P –  Ben Franchuk Oct 4 '13 at 8:29

I think PSU is a good candidate to blame. The good news is your don't need to respect the Video Card's recommendations for minimum wattage. You could get away with a 350W or 400W used power supply, as long as it is of a reputable brand. No-name PSUs are known for failing well below their rated power.

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The rating itself is indeed irrelevant for a GPU. What counts is how much power is output, specifically on the +12v rail(s). –  Hennes Apr 11 '13 at 6:59

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