# PC won't boot after power spike/outage



## SaigaShooter (Jul 18, 2005)

OK, so i was working in the office this morning and i went to print and as soon as the printer spooled up everything plugged into the powerstrip shutoff.
evidently the strip was a wee bit overloaded, I should have known better.

Anyway, after splitting things up between two different outlets, the only thing that won't come back on is the pc. I did not, smell or hear anything burn up when everything crashed.

The power supply is a 24 pin, 550watt Antec TruePower II. Because it has 24 pins for the mainboard power, I can't test it in any other system in the house, they are all 20 pin. If I set it up to use just 20 pin, I can power up other pc's, but I still don't know about the last 4 pins.

with the supply in another pc, i was able to check the other 4 pins, and am getting 5 and 3 volts. Seeing this I dropped the supply into my system, and tried to power up, still got nothing, By this time i thought maybe it was the motherboard, so i unplugged the power button, and tested the pins to see if they were getting power, they are 3 volts. I then attempted to start the system by shorting the two pins the same way the power button functions when it's pushed. the system failed to start.

Lastly i thought it may have been an addon card, or possibly a drive that failed, so I unplugged everything from the mobo, but it still failed to power up

So my question is, is it the supply that is fubar, or did something on the mainboard go? 

Thanks for your help


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## OMGmissinglink (Sep 24, 2006)

SaigaShooter said:


> OK, so i was working in the office this morning and i went to print and as soon as the printer spooled up everything plugged into the powerstrip shutoff.
> evidently the strip was a wee bit overloaded, I should have known better.
> 
> Anyway, after splitting things up between two different outlets, the only thing that won't come back on is the pc. I did not, smell or hear anything burn up when everything crashed.
> ...


You can use a 20 pin PSU on a 24 pin MB to test the pc.


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## SaigaShooter (Jul 18, 2005)

Yeah, i forgot that was doable.

I pulled out the multimeter and tested it while it was running, and everything checks out, and the host pc boots and runs fine. Looks like i cooked something on the motherboard.


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## Doby (Jan 17, 2006)

Have you tried a cmos clear?


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## SaigaShooter (Jul 18, 2005)

Doby, I did the cmos clear with the jumpers and it still did not power up.

Also, I got a new motherboard today, put it in, and I still get squat.
I suppose that it is possible for the additional 4 pins on the 24 pin connector to be damaged, but why then do they show correct voltages when the supply is put into a 20 pin system, and that system runs fine.

Could it possibly be that the powerswitch itself was damaged (i know thats pretty far out there)


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## Doby (Jan 17, 2006)

Explain exactly what happens when you push the power button, any fans spin or lights.

If possible test the yellow,orange and red wirer on the 20 pin connector this should be done when there is some load on the psu such as when it was in the other system or if the problem system at least has fans running.

Post these readings here.

To test the power switch, remove the connections from the motherboard and touch the 2 pins that they connect to with a screw driver, this should start the computer.

I think you already tried this with the first board but try it with the new one maybe the switch did somehow get damaged and also the old board too.

Let me know the results


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## SaigaShooter (Jul 18, 2005)

> Explain exactly what happens when you push the power button, any fans spin or lights.


The button clicks and thats it.



> If possible test the yellow,orange and red wirer on the 20 pin connector this should be done when there is some load on the psu such as when it was in the other system or if the problem system at least has fans running.
> Post these readings here.


Yellow 12.11v
Orange 3.37v
Red 5.15v



> To test the power switch, remove the connections from the motherboard and touch the 2 pins that they connect to with a screw driver, this should start the computer.


I tried this on both boards and got nothing.


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## Doby (Jan 17, 2006)

The voltage readings are normal and we know the psu works in another computer, you bypassed the case switch so it ain't that.

Make sure the extra 4 pin 12v connection from the psu to the motherboard is connected.

I would next remove the motherboard from the case and install only,,,

cpu with fan heatsink
psu
video card
1 stick of ram
ps2 keybord,ps2 mouse, monitor

Start the computer by touching the 2 pins again with a screw driver

This will eliminate the possibility of a case short and all drives&cards as being at fault. This is a test just to see it the computer will post (power on self test)


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## SaigaShooter (Jul 18, 2005)

Success!

I set up the old DFI mobo outside of the case and it still wouldn't power up, i then did the same setup with the ABit board and it fired right up.

I put the board in and screwed it in one at a time, and POSTed it aftereach screw. It is now running perfectly.

Thanks for your help Doby.


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## Doby (Jan 17, 2006)

Great glad you got it fixed, your welcome


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