Computer Shuts Off Automatically!

[ScottTheRobot]

So, I was trying yesterday to install a new hard drive. I'll admit, I didn't know what I was doing- and I never actually figured out how to get it hooked up. Anyhow, one thing I do know is to make sure I am grounded before I open a computer at all. I tried to make sure to do that. But, I admit, I was bumping wires and stuff around in this thing trying to figure out what to plug into where.

So, after my failed attempt, I tried turning on the computer, but the power button seemed useless. I flipped the power switch on the case off and then back on, and low and behold it starts up. But, then after a while the computer suddenly turned off. And, again, the power button wouldn't turn it on again for a few moments. Sometimes it will last 10 minutes, other times just 1 minute.

Well, I looked at a few different forums and thought it may be overheating for some reason- so I downloaded Motherboard Monitor 5 to check the temperature of the CPU, and right now it is at 43 degrees C. Since I downloaded the monitor, it has not restarted automatically- and it doesn't seem to be going in the direction of overheating either.

It was a self built computer (built by someone else)- 1.83 ghz, 1G ram, nvidia something card... i dunno- what info would be helpful?

Any ideas?

Thanks!

 

[mechBgon]

Welcome to the Forums One possiblity is that the power supply is not quite able to handle the system's new power demands now that you've added the hard drive. What is the full spec of the system, including the brand & model of the power supply (look on the label), and all the drives and cards, so I can get a picture of its power demands. If you can nail down the type of video card, that helps.

 

[ScottTheRobot]

I guess I didn't make that clear - i never actually got the hard drive plugged in.

Umm, lets see- the power supply looks like it's a SmartPower 100W output (model sl300s). It's an AMD Athalon XP 2500+, 1.83Ghz, 1G Ram. The motherboard is a Shuttle mainbord (MN31N) with nVideia nForce 2 IGP (i'm just reading this stuff off a box, I don't know what it means).

Strange- because it's been running now for about an hour without shutting down and the temperature is only at 41 celcius.

 

[ScottTheRobot]

To make it clear- I was trying to install a second hard drive. And we've been using this computer for over a year now without problems.

 

[cwos]

100 watts isn't very much, especially if you want two hard drives. How old is the power supply? It could be that.

 

[ScottTheRobot]

The power supply was bought with the rest of the computer off newegg.com about a year ago.

Yeah, there is only one hard drive in the computer though- one 40gb hard drive.

 

[mechBgon]

Is it maybe an SL300S? That would be a 300W Antec OEM power supply, not too bad but I personally would've gone a little higher.

My best guess at this point is that either you've partially unseated your main ATX power cable, or your square 4-pin ATX12V cable, or else you budged your heatsink inadvertantly and broke the seal that the thermal patch had established between the CPU core and the heatsink base. I have heatsink installation info on this page and also on this page, if you need a hand with that.

The thermal patches melt-to-fit the microgap between the heatsink and the CPU core... one time. If the gap is re-opened after that, you should remove the heatsink, scrape off all the used-up thermal pad, and apply a paper-thin coat of high-quality thermal grease in its place.

You can tell if the system's having a CPU overheat problem because your Shuttle will light up a red LED light on its surface and shut itself down. The LED is located where I highlighted in this image.

 

[ScottTheRobot]

Yeah, you're right- it's a 300W... sorry.

I'm incredibly impressed with your knowledge of all this stuff- thanks for the help. But, I'm not sure which cable is the main ATX power cable or ATX 12V cable- or where they are actually supposed to plug in. I think there is a good possibility that I could have partially unseated a cable though- because I was searching around trying to find a cable to plug into the hard drive- pulling stuff and what not.

 

[mechBgon]

Here's a visual rundown on the various cables: http://www.omnicast.net/~tmcfadden/guides/build/cables.html The main ATX cable is the big long 20-pin one. Just make sure it's fully pushed into its receptacle, ditto for the square ATX12V one.

 

[WiseOldDude]

Sounds like you might have been working on it with it plugged into the power. There was power on the motherboard even though the PC wasn't running. Not good practice...........