Computer tries to start but shuts down after 2-3 seconds

[joshSCH]

I built the computer that I am currently using last year, it is an asus A8n5x mb w/ amd 3200+ processor and 1 gig of ram.. its a great build, has never given me trouble before..

however, in the past week it has been very dificult to start it up. I usually put it in standby at night, and in the morning I will resume from the standby. Now, when I push the power button to resume from standby, the computer immediately shuts off. I try to turn it back on, it turns on for a few seconds, and then it turns back off...

I'm not really a novice, I've built several computers be4 and I have A+, mcp certifications and such (not like it really means anything).. so I have done some basic troubleshooting, but I cannot seem to solve this problem on my own. The computer starts properly (lights, fans, hd all start up), I tested the power supply w/ a multimeter, reseated all expansion cards, unplugged and replugged almost everything, and still the problem continues. It is the strangest thing I have ever seen... I press the power button, it turns on then immediately off. I work on it a little and still nothing, but then it will eventually boot up and work fine. It works normally until I put it in standby or turn it off, and then the next time I try to turn it on, I encounter the same problem...

Any thoughts/suggestions?? I still think it has to be some kind of a power supply problem since it never even reaches POST. Perhaps I am overusing the power supply? its a 450 watt that came w/ the case, and I have many components... sata hd, cd burner, dvd/cd combo, 3 fans,.. power supply problems are always the most difficult...

[dcc]

Have you tried using a different PSU?

[joshSCH]

i have one coming in the mail from newegg.. should arrive soon

[dcc]

Lit us know how it goes.

[joshSCH]

Alright, Today I had more time, and I was able to do some more indepth troubleshooting... I took everything apart, and put it back together one piece at a time, and found out that the problem only occurs when my hard drive is connected to my psu..

My hard drive is a maxtor diamondmax 10 6L200m0 200gb sata 1.5 gb/s
I'm not quite sure why my hd is all of a sudden having problems, and I have no clue why it causes the entire power to cut out... I'll look it up online, post if u have any thoughts/suggestions

[lasher511]

Sounds like you might just be overloading the PSU a bit try the same thing again but instead of unplugging the hard drive unplugg the CD drive and see if you get the same results. if you do then just get a bigger PSU for it

[dcc]

It sounds like the PSU's short circuit protection is shutting it down. This is a new one for me, I've never heard of a hdd having a short on the power side. But that's why we come here.

What happens when you hookup CD or DVD?

I still would like to see what the new PUS does.

[joshSCH]

the new psu has not come in yet... but, I do not think i am overloading my current power supply, I unplugged everything except mb and my hd, and I still get the same problem.

I think what dcc said about the short circuit protection may be true.. I've put the hd to my ear to try and listen, and I don't think it is actually starting up during the 2-3 seconds that the computer is actually on...

it's very strange.. I've never heard of a hd causing the entire computer to shut down, nor have I found anything online about it. I don't have another sata hd, so I can't test to be 100% certain that it is the hd..

Thanks for your interest, I'll let you know how the new psu works when it arrives

[dcc]

Do you have another computer you could install the hdd as a slave to see if it works? Do not place this in another computer with a different motherboard or more specifically a different chip set as a master, it will cause the OS not end of troubles.

[joshSCH]

ok.. the psu came in, and when I plugged it into the hd and mb.. it worked!!! So I have no clue wut the hell the problem is.. My old psu seems to just be having problems with my hd b/c it works fine with everything else. The hd that came in was only a 300Watt.. I just wanted to a buy a cheap one that I could test with. So.. any ideas on what the problem may be?

As to your idea dcc, I do not have another sata hd, but I do not think its the hd causing me trouble. Although through troubleshooting, I pretty much ruled out everything lol..

[dcc]

Glad to hear you have it sorted out. The PUS is the heart of the system, if you go cheap it will come back to haunt you.

[joshSCH]

I know, I guess I will buy a 500-600 Watt psu.. I kinda wanted to wait and see If I could figure out why my current psu is having trouble with my hd

[dcc]

PSUs will degrade over time, and yours may have been marginal from the start. The PSUs that come with cases don't enjoy the best reputations.

[joshSCH]

hah true that.. thanks for all your help

[runningshoes]

I have the exact same problem as josh.

I'm a complete computer novice so forgive me if I cant understand stuff.

My PC worked fine until I tried to directly switch it off by long pressing the power button at the front of the case. The computer went off but I couldnt put it on again through the power button. The PC starts automatically as soon as I put on the main switch on the wall. The fans turn, the hardisk spins, the cd in the drive spins but after a few seconds it all just goes off.

I've unplugged and plugged everything, cleaned and put back the heatsink, tried checking if it stays on without the cd drive/ram/hd(doesnt work with either of them unplugged)

The funny thing is that sometimes just like that it starts working fine. Just yesterday when it was not working, I slammed the cabinet really hard with my hand and when I put on the power it started working.

Another thing is that once it starts running it gives me no problem whatsoever, even rebooting doesnt cause problems, but once i shut down my PC it starts giving this problem again.

[moses8788]

I think its the dust that causes your PSU to trigger its short circuit protection. i think some way dust or an insect might have manage to go through the PSU an cause a short circuit