Computer won't turn on sometimes?

[blahraptors]

I've been trying to figure out what's wrong with my computer lately. Just like a car that refuses to start, my computer struggles to turn on. I press the power button and it turns on for a quick instant (lights on and everything) but shuts right off after. I press it again and the same thing happens. Finally, after repeating a few more times it turns on and runs as normal. Sometimes it just does not turn on no matter how many times I press the power button. But if I shut off the power supply, press the power button (so as to "clear the circuit"), switch the power supply back on, then press the power button again, the computer magically turns on most of the time. I'm guessing this has to do with a faulty power supply? My PS is an Antec Truepower ~400/450W and should still be under warranty. Any clues as to what might be wrong with my computer?

TIA

[Spor 13]

Anytime I've run into this issue, it usually turns out to be a grounding issue. Check your motherboard risers and screws. Once I used the wrong screws (they fitted perfectly tho) and thats what the issue was. Replaced the screws with the correct ones and it turned on perfectly. Check that you didn't miss any screws either.

Similarly, my friend has a computer that has a 6600GT AGP in it. Every time I plug in the Aux. power for the video card, the computer exhibits the symptoms you stated. Disconnect the Aux power and it turns on perfectly....except no video. Put in an older video card, and its works perfectly. My friend doesn't wanna buy a new case, so the problem still stands. I've never seen it before, but his case uses plastic risers.

Good luck! This is one issue that I really do hate to deal with.

[grappos13]

i have a pretty similar problem...

i have had this pc for over 2 years and have had no issues with it before... i left my pc for an hr today.. i come backand its shut down.. turn it on.. goes to regular desktop..but after 2 minutes, shuts down... again i restart it does the same thing...then for a while.. it would only start for like 5-10 seconds and then shut down.. i left it for a while (overnight) and when i tried it this morning.. it seems like its "booting".. like everything comes on.. but its not connected to the monitor or keyboard or mouse or anything.. if you have any idea what i should do, please let me know thanks...

[blahraptors]

Anytime I've run into this issue, it usually turns out to be a grounding issue. Check your motherboard risers and screws. Once I used the wrong screws (they fitted perfectly tho) and thats what the issue was. Replaced the screws with the correct ones and it turned on perfectly. Check that you didn't miss any screws either.

Similarly, my friend has a computer that has a 6600GT AGP in it. Every time I plug in the Aux. power for the video card, the computer exhibits the symptoms you stated. Disconnect the Aux power and it turns on perfectly....except no video. Put in an older video card, and its works perfectly. My friend doesn't wanna buy a new case, so the problem still stands. I've never seen it before, but his case uses plastic risers.

Good luck! This is one issue that I really do hate to deal with.

I've had this computer for 5 years now, and it has never happened before. It's not newly built. One day this started happening.. Could it be a part malfunctioning that's causing the problem? I replaced the original PS with this one, which is only a year or two old. Anyway I should check for loose screws. What are risers?

[jumran]

Sounds to me like the PSU might have gone bad.

[grappos13]

risers are the what the motherboard is screwed into at its corners and along the sides.. to make sure the mother board doesnt tocuh the case itself i think? certain cases dont even need risers.. i remember i was going nuts trying to get risers on a sunday when i was building my pc with a friend cuz my case didnt come with any.. went all the way to some random pc store at warden and 14th to get it.. turns out i didnt need it and i just screw it directly into the case...anways.. when i get home tonite.. im gonan try a few different things.. i really hope it isint one of my main parts that is busted.. i dont really play any of the hardcore new games.. usually older games.. so i didnt want to get a new pc till this one was 3 years old.. which is another 11 months away... hopefully i can fix it!

here is a basic link of stuff that i guess i will try tonite.. maybe u can too

http://pcsupport.about.com/od/findbysymptom/ht/wontstart.htm

[Hunt]

Sounds like a PSU problem to me as well, but it could also be a capacitor on your motherboard. Pop open your case and look for any blown capacitors, or ones that are really bubbled out on the top, as they should be completely flat. Sometimes after years of use, they just wear down and blow for no real reason.

[IoannI]

You might also want to check your RAM, it happend with me but my problem was the RAM.

[blahraptors]

thanks guys, will look into the case tonight. it could very well be the motherboard.. after all, it's been 5 years. i hope it's not the PSU because it's still kinda new. but if the PSU is the culprit does anyone know if i have to pay for S+H for a replacement unit from Antec?

i guess the right term to describe the problem is "electrical shorts". but the computer turns on after a random number of tries..? it's not that it does not turn on completely.. maybe it's the PSU after all :confused:

[IoannI]

Don't forget to discharge the PSU before you remove it!

[blahraptors]

checked the motherboard today.. doesn't appear to be broken in any way. i wish i had a spare PSU for testing. will a RMA with Antec cost me anything?

[Spor 13]

Hmm..I don't know if you have tried these yet, but I'd try these too:

If you're feeling adventurous and want to check something else, take out the PSU and on the 20pin (or 24pin nowadays) connector, short the green connector with one of the black wires. This will turn on the PSU. You can then measure each of the pins and make sure the voltages are alright. This really only checks that the PSU turns on as there is no load and it is not really working to provide the voltages.

Alternatively...to really make sure that you aren't shorting something with the screws, take the motherboard out of the case (Before you do this, make note of where the power button of the case connects to your motherboard. Usually its labeled PWR SW or something along those lines) and place it on a piece of cardboard with an anti-static bag on top of it. Take out the PSU as well, or if the cables can reach then less work for you ;). Connect the ATX 20pin cable to your motherboard. Take a paperclip or some sort of wire, and short the two pins on the mobo that were connected to PWR SW (the power button of the case). If it turns on, then the PSU should be good. You can try loading up your PSU even more by adding all your drives.

[blahraptors]

I don't mean to bring this thread back up again but just wanted to let readers know that the problem was the PSU. It's too bad I had to retire my Antec TruePower II 480W. Compared to the cheap Thermaltake I got today, it was ALOT quieter. This Thermaltake is very very loud and I wished I shelled out a bit more for a quieter one, however, this one was only $30 after MIR. So anyway, if you are reading this because you have a similar problem, you might want to think about getting a new PSU.

Now.. how do I edit thread title?