New computer build wont power up.

[RearAdmiral]

I just completed my new computer build and when I pressed the power button it didnt power up. The only thing I can think of is that I have the atx power switch in the wrong place. It is in an awkward place but would that cause the computer not to turn on. The motherboard's LED is showing that it is receiving power though.

 

[FullRoast]

If the motherboard is indicating that it has power, double check the switch connections to the motherboard. You may have some connectors on the wrong pins.

 

[gameboyzz]

check the clear cmos jumper..

 

[RearAdmiral]

Well when I turn off the power supply, then turn it back on, the computer starts for a few seconds, then shuts off. I was playing with the atx power switch, the thing with the two cables, and it turned on for a while, but I shut it because the power button still wasnt working.

 

[mechBgon]

Originally posted by: RearAdmiral
Well when I turn off the power supply, then turn it back on, the computer starts for a few seconds, then shuts off. I was playing with the atx power switch, the thing with the two cables, and it turned on for a while, but I shut it because the power button still wasnt working.

Two possibilities come to mind here:

1) Maybe your heatsink is reversed, resulting in an instant CPU overheat and automatic shutdown (if it's an AthlonXP or Duron). Check here and look at the SocketA heatsink installation guide.

2) Maybe your case's power button is faulty, and is making continuous connection when it's supposed to be just a momentary-contact switch. Double-check what pins your Power Button should plug into (it's in the mobo owner's manual) and then use a piece of metal to make a direct momentary contact between those two pins, instead of using the case's Power Button wire to do it.

 

[So]

Sounds like you either have

1: There may be no fan attached to the CPU_fan header. Find the three pin CPU_FAN header on the motherboard and make sure the Heatsing fan is properly connected to it. Some boards won't let you boot without a fan connected to this header.
2: Motherboard shorting on a case standoff. Remove your board from the case, put it on a dry nonconductive surface (wooden table) and install:
CPU
HSF
Vid. Card
1 Stick RAM
KB
Mouse
Monitor
Power Supply
Then, Try to boot (you can start it up by momentarily shoring the two pins for the power switch on the board with a flathead screwdriver).

 

[RearAdmiral]

Got it to work, I had the switch a pin off.

 

[cy7878]

things to check:

1. when the power supply is on, is there lights on the MB indicating it is getting power?
if you have a small LED light on, then it's not the power supply problem, go to step 2.
if you have no LED light, you have a bad PS, and get a new one, before proceeding.

2. when you press the power switch, does the fan (CPU or whatever) come one?
if you do, the switch is connected correctly, go to step 3.
if not, the switch is either bad or not connected correctly, fix it.

3. if the fan comes on, do you hear beeps?
if you do, the MB is okay, go to step 4
if you don't hear beeps, the MB is bad, get another one.

4. if you hear beeps, but no screen, a number of things can be wrong, but if you approach it systemmatically, yo can generally isolate the problem to just 1 component. the usually coprit is RAM, CPU, or video. This is when having a spare system to swap parts from is helpful.

But from your description, I say your MB is fried. get another one first before changing other pieces.

Good luck

 

[So]

okay then.