Whenever I try to turn my computer on, nothing happens. I know its not the power source because the LED on my motherboard is lit. I've tried different power switches, and they still didnt work. I've tried unplugging and plugging back all of the plugs and pins, with no avail. Any suggestions?

Hi there

Just because the motherboard LED is lit, doesn't necessarily mean that the PSU is OK.

What do you mean when you say you've tried different power switches?

Could also give us some basic specs including the motherboard make & model if possible please? Or, if you have a branded system such as a Dell for example, let us know the brand & model name/number.

Can you also tell us if anything changed just prior to the problem starting? e.g did you change or add any hardware? Was the system working normally before this problem first occured?

Sorry for stalling when you responded so fast!

As for power switches, I dont know what else to call them, but the button you press to power on your computer. I thought maybe that was faulty, so I tried a different one.

The motherboard is an Asus P5W DH Delux Intel 975X.

And lastly, I didn't change any hardware before the problem came up.

OK, the first thing I want you to do is clear the bios. Disconnect the power lead from the PSU, open up the case then disconnect the main ATX lead that connects the PSU to the motherboard.

Near the bottom right corner of the motherboard (near where the SATA connectors are) you'll see a row of 3 pins labelled CLRTC. There will be a plastic jumper cap covering 2 of the pins (pins 1-2).
Move the jumper cap so that it covers pins 2-3 instead. Leave in this position for about 30 seconds, then return the jumper cap to it's original position (pins 1-2)

Reconnect the internal ATX power lead, then the external power lead & try to power the system on again.

If it still won't power up, follow the instructions below EXACTLY:

1) Disconnect the main external power lead, then disconnect ALL of the PSU cables inside the computer. i.e. disconnect the power from the motherboard, drives etc. Leave the power connected to the CD/DVD drive however.

2) Next, find a bare metal paperclip. Straighten the paperclip out then bend it into a tight U shape.

3) Get the main ATX power connector, which should already be disconnected (this is the 20 or 24 pin rectangular plastic connector that plugs into the motherboard). Look for the single green wire.

4) Once you have located this wire, plug the external power lead back in to the rear of the PSU

5) The LED on the motherboard should now be lit up as normal.

6) Insert one end of the paperclip into the underside of the ATX connector where the green wire is. Insert the other end into the underside of any one of the black wires. Make sure you push the paperclip in as far as it will go.

This will bridge the soft power connector (the same as pressing the power switch on the front of the computer).

Let me know if the PSU powers up - check to see if the fan inside the PSU is spinning etc. You can just pull the external power lead out of the rear of the PSU to turn it off again.

Alright, I'll get back to you in about a week.
I sent it to my friend to see if he could have a go at it, and I'll try what you listed when I get it back (unless its already fixed)

Untill then, thanks

I have the same problem... Followed all advice and the computer still wont work (power supply works). Does this mean I'll have to replace the motherboard or is there other possibilities? Thanks

It's a Dell dimension 8400.

Welcome to G2G randomscreenname

Can you start your own topic please so we don't get confused over who I'm giving advice to! Just start a new topic and tell us exactly what the problem is and we'll do our best to help you

Heh, yay bumps.

Well, I tried what you told me, except I couldn't find a paper clip so I just used a different bare wire ( didn't think it would matter, but just informing you).

I didn't see how the MB light was supposed to be on (step # 5) when it was disconnected from the PSU, so I just continued when it wasnt on. After I tried everything you said, it still refused to start up. No fans spinning, MB light still off, etc.

I'm guessing the PSU has to be replaced?

The motherboard light won't be on because as you pointed out yourself, the PSU isn't connected to it. All you need to check for is whether the fan inside the PSU was spinning.

Assuming it wasn't, then yes you almost certainly need to replace the PSU