Motherboard or PSU or something else?

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01-04-2009, 08:20 PM
Nick2.1

Motherboard or PSU or something else?

I bought a PC for my girl friend because she wanted to play games with me on line. I bought her the same basic setup I had except for the motherboard(I have an Asus and her's is a Foxconn). After I put it together I flipped the switch and the computer waits a second and powers up for a fraction of a second and stops. I took it apart and put it back together and this time no start what so ever. I used a paper clip on the 13th and 14th pin for the 24 pin connector and the PSU started up perfectly. The only conclusion I can come to is the motherboard, I just need some second opinions if you can give them. And I have to use this smiley :a2a:
01-04-2009, 08:53 PM
MrTroy

Take the mobo out of the chassis to make sure there isn't a screw or something under there causing a short. It doesn't even spin the fans at all? Take out all unnecessary components, leaving the CPU, ram and Video card (if it isn't onboard) to see if you get any power. Heck, if need be take it all out of the chassis, set the mobo on an anti-static bag, hook up the PSU to the mobo to see if you can get some fans spinning.

I would guess it is getting shorted out somewhere, or it is a bad mobo. But it's hard to say without testing.
01-04-2009, 08:57 PM
Nick2.1

Quote:

Originally Posted by MrTroy

Take the mobo out of the chassis to make sure there isn't a screw or something under there causing a short. It doesn't even spin the fans at all? Take out all unnecessary components, leaving the CPU, ram and Video card (if it isn't onboard) to see if you get any power. Heck, if need be take it all out of the chassis, set the mobo on an anti-static bag, hook up the PSU to the mobo to see if you can get some fans spinning.

I would guess it is getting shorted out somewhere, or it is a bad mobo. But it's hard to say without testing.

I've taken it all components out one by one tests. It's 750w PSU, so not enough power isn't the thing(and it's a single rail). I have taken it out and put it on a non static bag and it's no go.
01-04-2009, 09:06 PM
MrTroy

I guess the final nail in the coffin would be to try it with another PSU that you know works. Obviously if it powers than it is a bad PSU, if it does not, it is likely a bad mobo unless something is being overlooked.

Even if it didn't have RAM and a CPU and couldn't POST, you should still get power and CPU and/or Chassis fan spinning. Just for the heck of it pop out the CMOS battery for a moment and pop it back in as well.
01-04-2009, 09:27 PM
Nick2.1

Quote:

Originally Posted by MrTroy

I guess the final nail in the coffin would be to try it with another PSU that you know works. Obviously if it powers than it is a bad PSU, if it does not, it is likely a bad mobo unless something is being overlooked.

Even if it didn't have RAM and a CPU and couldn't POST, you should still get power and CPU and/or Chassis fan spinning. Just for the heck of it pop out the CMOS battery for a moment and pop it back in as well.

Well if I use a paperclip I get the chassis fan working. Other PSU doesn't work. I'll try the CMOS.
01-04-2009, 09:45 PM
MrTroy

Quote:

Originally Posted by Nick2.1

Well if I use a paperclip I get the chassis fan working. Other PSU doesn't work. I'll try the CMOS.

When I say Chassis fan, I mean the fan or fans that are in the case. NOT the fan in the Power Supply itself.
01-04-2009, 10:45 PM
Nick2.1

Quote:

Originally Posted by MrTroy

When I say Chassis fan, I mean the fan or fans that are in the case. NOT the fan in the Power Supply itself.

Yes, I know.
01-13-2009, 10:45 PM
thank mr skeltal

See the recent thread I made, I had a similar problem. I'd recommend you break it down to error-check from the basics of the motherboard only and work your way up. That is how I found a short in the power button on the front of my case was the cause of all my problems.
01-13-2009, 11:13 PM
MrTroy

Yea, I think he (Nick) took the whole motherboard out of the case and sat it on an anti-static bag, and it STILL wouldn't spin the fans, it's probably a fried motherboard. I mean, if it is just a motherboard/CPU and the CPU fan, and you get no power and there is not short, and you KNOW the PSU works via hooking it up to another PC (which he did), than it is a bad CPU, RAM or bad Motherboard.
01-13-2009, 11:37 PM
Nick2.1

I'm thinking it could be the cpu or memory, but I'll know thursday, taking it to a computer store for a diagnostics. I sent the motherboard back and with the new one it still doesn't work, so I decided for the diagnostics test to pin-point the problem.