Computer Won't Turn On

[Virtualbody1234]

On the back of the tower there is a switch on the power supply. Is that switch on when you press the button?

[Smurfette]

Originally posted by Infested Cats+14 November 2003 - 02:51--></div><table border='0' align='center' width='95%' cellpadding='3' cellspacing='1'><tr><td>QUOTE (Infested Cats &#064; 14 November 2003 - 02:51)</td></tr><tr><td id='QUOTE'><!--QuoteBegin-_John_Lennon_@13 November 2003 - 21:44
Have you determind yet though that power is actually going to the power strip?

The power strip is getting power becasue 1) the light on it is lit and 2) everything else that&#39;s plugged into it is functioning.[/b][/quote]
But have you...
3) swapped tried the computer plug in another socket on the strip? There could be a fault with just that socket.

Also, use a multimeter to check the pins on the mobo that the power switch connects to, to make sure that the small voltage is being supplied to the switch. If there is a voltage check that it&#39;s being returned from the power switch when you press it. If there isnt, check that the small voltage is actually coming from the power supply to the board. You will need the mobo&#39;s manual for this, to know which pins to test.
If you&#39;ve got power going in from the PSU but none going to the switch, it&#39;s the mobo at fault.
If there is power to the switch, check the pin that returns voltage to the PSU when the power button is pressed and if there&#39;s none when you press the switch or join the power switch pins, the mobo is at fault.
If there&#39;s no small voltage from the PSU check its fuse - not just the one in the plug, there is one inside as well. Many multimeters will check fuses with a &#39;continuity check&#39; function, or even by checking for resistance (infinity = faulty). If the fuse is OK and you&#39;ve made sure there is power to the PSU, the PSU is faulty.

I don&#39;t know if you followed that but here&#39;s a very simplified explanation to help clarify how ATX computers get &#39;turned on&#39;...
The PSU supplies a small voltage to the mobo and the mobo supplies it to the power button on the case.
When you press the power button, that small voltage returns down to the other pin on the mobo that the switch connects to.
When the mobo detects that return voltage, it sends another small voltage to the PSU.
When the PSU detects that small voltage, it turns on the +12 and +5 voltage lines, the it&#39;s fan comes on and, hopefully, the computer comes to life.

That should help anyone troubleshoot power problems but please note: If you are not sure what you are doing or not confident working inside an electrical appliance with mains voltage supplied to it - leave the damned thing alone and get a professional in.

[SciManAl]

If you are not sure what you are doing or not confident working inside an electrical appliance with mains voltage supplied to it - leave the damned thing alone and get a professional in.

you mean like my cousin earl??