BleepingComputer.com: Computer Doesn't Turn On

Hey guys.

This topic concerns my Gigabyte Desktop Computer.

It's approximately 3 years old. Windows 7, 2GB RAM, 2.2GHz processor, 1GB NVIDIA Graphics Card, 240V Power Supply.

I decided to turn it on today and got no lights, no noise, no fans, nothing. I tried a few of the general troubleshooting steps:

• Switched on all switches.
  
• Swapped power cords.
  
• Lamp test (to test I was getting power).
  
• Compressed air to clean out the computer of dust etc.

No success. The only thing I did notice was that occasionally the power supply unit emits a high pitched noise. I'm guessing the power supply unit is dead but before I buy a new one I wanted to double check.

EDIT: I just tried the power supply in a different computer and it worked with no weird noises...so I guess it's something else.

What should I check next?

Thanks.

This post has been edited by The Dark Knight: 10 July 2011 - 10:34 PM

Sometimes when power supplies are drawing too much power they emit a high pitched whining noise. There could possibly be a short on your motherboard.
If the power supply works in another computer, it's probably safe to bet that your motherboard has some issues. Check for blown capacitors.

Instead of purchasing another power supply right away, see if you have a friend that can lend you one that's 240W or greater, and test with that.

-Thumperrr

This post has been edited by Thumperrr: 12 July 2011 - 07:55 PM

Ok. In the event there is a blown capacitor, would it be cheaper to just replace the whole motherboard rather than trying to replace the capacitor?

It would certainly be cheaper to replace the capacitor.. Assuming you have the proper soldering equipment and such. However it's only postponing the inevitable.
However, a single blown capacitor wouldn't cause the problem you're having. (Now, if you open your case and see every cap blown... that's a different story)
The reason i mentioned to check for blown capacitors is that it's a tell tale sign that your motherboard is going down hill.

Did you check the PSU Molex connection tot he motherboard before you removed it? Was it seated properly?

I didn't notice a lot of damage to the motherboard so perhaps it is just the one that has blown.

@s1lents0ul: Yes, the Molex connection was seated properly. I made sure it was when I put the PSU back in as well.

This post has been edited by The Dark Knight: 15 July 2011 - 05:13 PM

A motherboard can be damaged even if there's no visual evidence.
That's why everyone preaches about ESD. You won't see it, hear it, or feel it happen, because an electrostatic discharge 3000 times less than what we can feel can damage a circuit board. So it could very well be bad even if you can't see it.