So out of the blue (there might have been a slight power surge, but I’m not sure), my desktop computer shut itself off and did not immediately reset. Upon hitting the power button, the “working” light came on, but not the “power” light. In addition, there was no POST, not even a single beep. Heaving a great sigh, I reseated all of the power connectors, checked all of the memory banks, checked the CPU’s seating, and both the video cards. Nada, zip, zilch, nothing. All of the fans come on, all of the pretty blue LEDs in the case (and powered by the power supply) turn on, but the computer just sits there and does nothing. I’m pretty sure (though it’s perfectly possible I’m mistaken) that it’s either a) the power supply or b) the motherboard. I’m a college student, so replacing both to find out that one or the other was perfectly fine is less than ideal. Is there any way to figure out for sure what the problem is? Even better if you can tell me how to fix the problem without buying new components.
Thanks for your help.
Generally a power supply failure is just that–no power. Sounds to me like the motherboard is in trouble and possibly you lost the BIOS. Try removing the battery in the motherboard that gives power to the BIOS. It might be that all you have to do is reset it. If you have lost the BIOS, I’m not sure how to fix it (that’s why I got a motherboard with dual BIOS.)
I’d still lean toward power supply (PS failures are probably 50-80% of the computer failures I see), but find out for sure: Find an EE major, and have them bring their multimeter over. The power supply taps will be labeled for their voltages, just check to see if they’re producing what they say (within a few percent, anyway). If you don’t know how to use a multimeter, let the EE major do it – they may be unwilling to let you use it yourself, anyway.
Next, remove ALL the RAM, and see if you get to POST. I’ve seen fried RAM chips do this. I don’t think this is likely.
If it is the motherboard, it’s harder: if you built the computer yourself, the motherboard will probably have a small switch, dip switch, jumper, or something like a pushbutton circuit breaker on it that resets (and possibly even reflashes) the BIOS – even many cheap motherboards have them. The motherboard manual (available online if you didn’t keep it) will tell you. Luckily, motherboard replacements for standard cases are cheap, if nastily time-consuming.
If it’s a name-brand PC, their custom motherboards often don’t have these. You’ll have to call their support at this point.
Oddly enough, I had the same issue a while back (covered in this thread). After my comp shut off, all lights, fans, etc, would come back on, but no screen.
Lightbulb came on after I noticed 2 things:
1)Case lights were (occasionally) flickering very slightly after the power came back on. It was barely noticeable, and I don’t think they flickered every time.
2)When I turned off the power supply switch in the back of the comp, then turned it back on, the machine would not power up. I had to wait sometimes over an hour after turning the power supply switch back on before the comp would start.
Problem turned out to be a bad power supply. I installed a new one last week (around $100) and haven’t had any problems since.
I reset the BIOS (moved a jumper, unplugged the machine and removed a battery), and no dice, and removing the RAM to try and get a POST got no where. One of my room mates is an EE, so I’ll see about getting a multimeter, but I might just be able to sneak a cheap one out of a freshman physics lab. Thanks for everyone’s help! If it is just the power supply, it’ll be really nice to just swap it out. The motherboard, if anyone is keeping score, is an Asus M2N-SLI Deluxe.
If it’s the same issue I had for a long time, it’s your video card failing to initialise. Which is a symptom of a dying motherboard.
My solution was to heat up my motherboard, which seemed to warp it into (I assume) causing all the connectors to touch and allow it to initialise. But this is not a recommended method.
I think it’s probably new computer time.
How about speaking to your college’s IT department to see if they’ve got a spare PSU you can borrow?