Need Help With Custom Computer I Am Making?

Question

I am making my first desktop computer. I followed the directions and put everything in but the computer would come on for 4-5 secs and then go off.

Then I decided to take out everything except the mobo and the power supply connecting it but its still doing it. It will come on and then go off. The mobo's light is on (green) so it is getting power.

The motherboard is ASUS M2N SLI and the power supply is Antec ATX 650 Watt. The case is Antec P180 if that makes a difference. The power supply's fan also comes on.

I am just wondering what maybe wrong as I have spent 3-4 hours on this and can't figure it out. Can someone please help me out on this?

I have a cpu cooler on there on top of the Athlon X2 5200+ and it will do the same thing. It will come on for the 4-5 secs and then shut off. So I don't think its the cooler.

Answer 1

The online support page for Asus is down for questionable maintenance, so you need to look at your user manual to verify what I suggest.

Some motherboards come with Fan Off Control, or FOC, which shuts down the computer upon powerup if no CPU fan is detected. In order for the CPU fan to be detected it must be powered from the motherboard's CPU fan power connector. If you have your CPU fan being powered directly from your Power Supply Unit, or PSU, then your motherboard may not be detecting a fan and shutting down to protect itself. There is a multi-combinational key set you can press to overcome this shutdown, but for your motherboard I don't know what it could be. You need to look into your manual to see if you can find if your motherboard has this protective feature and what the key combination is to disable it. Once you can enter Bios you can permanently disable the FOC feature so your computer doesn't immediately shut down.

If your computer doesn't have FOC then it is shutting down due to overheat. There are not many other reasons why a computer would shut down, unless your power supply is faulty.

UPDATE:
Since Asus support is down, I took a look at a picture supplied by a vendor of the motherboard and found what power connectors come with your power supply.

I suspect that you have not plugged in your 4-pin CPU power connector. Follow this link to locate it. http://www.newegg.com/Product/ShowImage.aspx?Image=13-131-013-02.jpg%2c13-131-013-03.jpg%2c13-131-013-04.jpg%2c13-131-013-05.jpg%2c13-131-013-06.jpg%2c13-131-013-07.jpg&CurImage=13-131-013-04.jpg&Depa=0&Description=ASUS+M2N-SLI+Deluxe+Socket+AM2+NVIDIA+nForce+570+SLI+MCP+ATX+AMD+Motherboard+-+Retail

Answer 2

My husband and I recently built a computer from the ground up too and are in the process of building our second one. My husband is also a Master certified Automotive technician. While automotive is a bit different than computer technician, these days cars have many computer components. So, I just wanted to give you a bit of background. While neither of us would claim to being any type of computer technician or expert, we do each have some degree of experiance.

I have read all of the responses here, discussed it with my husband, and after a day or two mulling it over, I have to ask a couple of questions. Or, give some other possible options of what this could be.

Did you ever get the OS installed into the machine? If so, did it ever boot up properly? If you didn't yet install the OS, at exactly which time did the machine appear to shut off? If the MB is showing a green light, which indicates it is ON, then why do you assume it is OFF? Is the light actually going off when it appears to shut off? When you turn it back on, is there any type of delay or is it an immediate ON? Does the power supply fan stay on after it appears to shut down, or does it go back off too? Does any part appear to indicate it is on, but all is dark?

If it is an immediant ON without any delay, we think it is a motherboard issue. If it has a delay from the moment you switch it on, to the actual time is comes on, then it could be a overheating problem with the power supply. These are all guesses now, but I would reccomend you start which of the above it closely matches and go with that peice of hardware.

As you are down to just these two peices of hardware it is one of these two, or it could be the onboard video. If the green light still indicates ON, but it appears to be OFF, then your mother boards onboard video may not be soldered properly, or a connection could be faulty which is not allowing it to show any graphics or words of any type, just a black screen as though the machine were off.

Regardless it HAS to be either the power supply OR the Motherboard which is faulty. If it is the Onboard video, then it is a part of the Motherboard and therefore a faulty motherboard.

The easiest thing to do is put a different power supply on and see if it all comes on, stays on, and words come onto your screen. If you add another power supply and you have the same issue, then it is the motherboard, either the Onboard video or some other component of the MB.

Once you try a different power supply and it either works or it doesn't work you will know what your next step should be. Either take the power supply back or return the motherboard and get whichever is faulty, replaced. We personally think it is going to turn out to be the motherboard. Why? Because we "think" you are saying that the light on the MB stays green, which indicates the power supply is good. Then again, we could be completely mistaken in what you were trying to convey when you wrote that.

Good luck and much fun building your computer. This may seem very frustrating now, but if you think of it more as a learning experiance then it is an opportunity to learn more than you would have had it just all come together without issues. However, there is something to be said about it all coming together without any issues at all, too! lol

Answer 3

first thing take everything out and start over. make sure the CPU is supported as well as the ram. Connect only the power and power button cable and speaker. look for the light on the monitor to turn from yellow to green and you will listen for memory beeps. if it keeps beeping then there is a problem.

Answer 4

just check all the connections. I have built many computers and this ALWAYS happens to me, and i spend an hour or 2 unplugging and re-plugging and eventually it will work. Sounds like it's the RAM. Take it out and make sure you lock it in 100% securely.

Answer 5

only connect the power supply, processor, ram and hard drive. turn it on and let it load, then shut off and connect everything else

Answer 6

check if your CPU fan is connected, it will go off if CPU over heat