When Power Supplies go Bad
When a power supply goes bad, the symptoms can be mysterious and confusing. The computer might hang. It might shut off all by itself. It might suddenly reboot. I experienced these symptoms about 6 months ago when an aging system that performed without hiccups for the past year or so started turning itself off at random times. If your PC starts to exhibit such annoying activities, you just might have to replace the power supply otherwise known as the PSU.
Before you do, consider what you’ve done in the recent past. Have you been overclocking the CPU or chipset? Doing so can quickly eat up precious wattage and overtax the poor PSU. Have you added lots of stuff to your computer, such as a beefier graphics card, a bunch of bus-powered USB peripherals, a discreet sound card, multiple hard drives, or anything of that nature? Try removing or disconnecting some of that stuff and see if the computer’s behavior smoothes out.
If, by chance, you’re running in SLI a pair of Nvidia-based cards that require not one, but two PCI Express power leads, try this: Disconnect the PCI-E leads from the inner connector on each of your two graphics cards. With power coming only from the outermost connectors (those nearest the front of the PC), the computer should still boot an operating system—it just won’t have the muscle to crank out demanding 3D graphics. If the computer stops rebooting, handing, shutting down, or whatever it was doing, you’ve just diagnosed a weak power supply.
What to do? Grab a higher-wattage PSU (or one from a trusted manufacturer)—if you’re currently using a generic one. Trusted manufacturers include Cooler Master, PC Power and Cooling (now part of OCZ), Antec, Thermaltake, and a number of others. Or cut down the power demand in your PC. Lose one of the graphics cards if you’re rocking an SLI or CrossFire system; replace high-demand parts with lower-wattage parts; and stop overclocking.
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POSTED IN: Articles, Diagnostics, OS Troubleshooting, Purchasing Equipment
1 opinion for When Power Supplies go Bad
Brian A
Mar 24, 2008 at 12:26 pm
You might also want to consider investing in a power supply tester. I picked one up for less that $20USD, back when I was working independently.
In my case, the power supply had lost its 12V leg, but the rest of it was working properly. This meant that anytime any higher-powered devices (like a DVD-ROM) tried to power up, the entire voltage net sagged, causing the PC to reset and reboot. The tester immediately showed me the missing 12V. A quick trip to buy a beefier power supply fixed the problem.
I have quite a few 300W supplies laying around from upgrading customers machines, but because of all the hardware hanging off that machine, I resisted the temptation to just ‘make do’. A new supply gave my primary machine a new lease on life.
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