I my quest to find out what on earth is causing random lockups, I'm starting to think it was the power supply. The reason is that the problems started soon after I put my graphics card (old Radeon X800) and the demand for power went up. Recently I've kept one monitor disconnected (was a dual monitor setup) and it hasn't locked up at all.

Before you ask about the card, the lockups don't just occur when doing graphics heavy stuff like gaming, its during normal but heavy operation. I could be viewing flash, encoding video's, fragmenting, running a virus scan, remote desktop with semi-heavy application running, or other things that don't use the card.

Unfortunately I can't tell the exact wattage of my PSU. It seems this case (old Emachines W2060) used several different power supplies and didn't list this information on the PSU itself. There's 250w (although its a stretch), 300w, and 480w PSU's available, but I'm not sure which one it is.

So my question: Could an underpowered power supply cause lockups? This would mainly be under heavy load but could also be randomly. This would happen after anywhere from an hour to 6 hours of use.

  • What is a "lockup" in your case? If you have sound playing in the background, does it continue playing during the lockup? What happens to the screen? How long do they last? – Sasha Chedygov Oct 5 '10 at 1:27
  • are you sure you have the most up to date drivers for that card installed? – MaQleod Oct 5 '10 at 1:32
  • @musicfreak By lockup I mean everything freezes. Music and programs stop, input is ignored, and my external hard drive activity light even dims telling me that its safe to disconnect. @MaQleod Yes, the drivers (and all other system drivers thanks to DriverMax) are updated. – TheLQ Oct 5 '10 at 1:55
  • Btw, this isn't because of the operating system (Windows XP). I did a full reinstall recently and the problems carried over. – TheLQ Oct 5 '10 at 1:55
  • If it's a Pentium 4 / P4 Celeron / AMD Athlon-era emachines model, be aware that the Bestec-branded power supplies of the time were notorious for misbehaving and when the eventually 'blew' (often with a bang) they tended to take the motherboard with them. I would certainly check / change the PSU. – Linker3000 Oct 5 '10 at 8:15

I think you are almost ccertainly right that the PSU is the problem Removing the case side will show you the current PSU and you can see what you have to work with. How many devices do you have - HDDs, Burners, etc? If you aren't sure try using a system profiler e.g. http://www.piriform.com/speccy Once you know what devices you have there are a number of websites that will calculate what power supply you need for your system

Type Power supply calculator into Google for the calc sites E.g. http://educations.newegg.com/tool/psucalc/index.html

If you do the tests and find that your PSU should be ok for your system config then you have 2 paths 1) is that the PSU is faulty Probably the only way to be sure is to trouble shoot by trial and error or by replacing 2) PSU isn't the problem - whole new kettle of fish

At least if you profile your system and then work out what power you need versus what you have you can work out whether that is the issue Hope that helps :)

  • This has a lot more options for the calculation: extreme.outervision.com/psucalculatorlite.jsp – Mircea Chirea Oct 5 '10 at 3:46

The monitor doesn't draw the power from the powersupply itself, but it's just re-routed AC mains to the monitor.
My experience says, first update your gfx card to the latest drivers.
Is your case well cooled? Insufficient cooling might also cause this issue. Also, sometimes the default fan settings of the gfx card is set too low. Rivatuner is used to see core temperatures and tweak fan speed for NVIDIA cards, I don't know one for ATI cards.

-Samrat Patil


As others have stated there are several possible causes, and an underpowered or faulty PSU is one of them. So the simple answer is Yes, an underpowered PSU can cause lockups and other problems, it's also bad for the health of the PSU to regularly/constantly overwork them.

I can say this for definite because my PSU failed on me about 3 weeks ago, after ~2yrs service in the same machine with no hardware changes.

The issue presented itself as green specks/lines over screen and full system lockup, this happened even when not under load. System would work fine for short periods (I didn't really push it) but I did on at least one occasion receive the specks on the BIOS screens as well - instantly ruling out anything OS or driver related.

Luckily for me, I was able to borrow a PSU out a friends desktop to test with, and that instantly fixed the problem. One brand new PSU later - all fixed.

Obviously, graphics cards tend to be high drain, but if other components were underpowered instead this sort of problem may manifest with entirely different symptoms.

So, if you can get your hands on one, test with another (suitably strong) PSU and see if the problem persists, if not you have at least ruled out this possibility.


Power issues can do an array of things to a computer, so yes, it can cause lock-ups, but that isn't necessarily what is happening here. It is not uncommon that a new graphics card can cause power issues with a computer, but usually it just won't turn on or will just turn off, not hang. When I worked in installation, the majority of emachines needed new power supplies when installing a graphics card to use in place of the on-board card as they typically had the minimum installed (about 230W). Considering your power supply is almost certainly unregulated, it probably creates that randomness that you are experiencing. On the other hand, it could be an issue (and more likely is) with the port your video card is installed in, the video card itself, or the drivers. You have not really provided enough information to determine much.

  • The graphics card drivers (and all system drivers thanks to DriverMax) are fully updated. The card usually runs dual 17" CRT monitors at 1124x768 resolution and Windows XP, but recently is powering only one monitor and locks up less. Usually lockups occur during gaming, but also sometimes during non-video but intensive applications. Lockups also leave the screen up, while graphics card overheats (stress tested for 30 mins, lasted 10-15) crash the card and leave a blank off monitor. If its the card its a very strange issue. – TheLQ Oct 5 '10 at 2:02

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