Geek Tested:

PC Won't Stay On

Posted 10/07/09 at 01:45:22 PM by The Maximum PC Staff

Ask the Doctor Logo Ninety percent of the time, when I attempt to turn on my PC it powers up for a second then immediately shuts down. The other 10 percent of the time, it boots but I get no video signal. I’ve had it looked at by a local shop, which tested each component individually (except the mobo) and found them working properly. I’ve done some troubleshooting myself and I’ve gone through the wire diagrams and everything seems to be plugged in right. However, it doesn’t sound like my hard drive is turning on. I was hoping you had some ideas before I try a new hard drive. I’ve already put in a new power supply but that didn’t change anything. Any ideas?

—Shane Mitchell

The PC shutting down directly after powering it up may be the result of a short circuit somewhere in the system. Since you tried a new PSU, it’s possible the plug that you’re connecting to the PSU is shorting it out, causing it to turn off. So, unplug everything in the system—especially those Molex auxiliary fan connectors and hard drive power connectors—except for the main power connector, ATX 12V, and your GPU, and try powering it up. Another common problem is the board shorting out from a badly placed mount. If you put more than nine board mounts in your case and you used only nine screws to screw it down, the extra mount(s) could be the issue. Finally, check the CPU heatsink for a solid connection and verify that the thermal paste is still in place. If the thermal paste has “pumped out” or the heatsink is not making firm contact, the CPU could be overheating and shutting down. Finally, make sure that the main power connector and ATX 12V connectors are firmly plugged in. If it still fails, you may indeed have a bad board.

SUBMIT YOUR QUESTION Are flames shooting out of the back of your rig? First, grab a fire extinguisher and douse the flames. Once the pyrotechnic display has fizzled, email the doctor at doctor@maximumpc.com for advice on how to solve your technological woes.

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Frustrating
Submitted by Bender2000 on Wed, 10/07/2009 - 11:49am

My friend had a similar problem, we diagnosed it finally when the video card caught fire. Bad capacitor. Look for bad caps on the MoBo since everything else was checked. Also, if it is a bad HDD then using a live disc of Ubunto or Knoppix will let you boot. Usually a bad HDD will leave you with a blinking cursor but it boots. Something with the video circuit shuts it down early.

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