Just recently on the Technibble forums we had a young soon-to-be technician who said he thought he was “pretty freakin good” at computers. Many of us told him that he was yet to encounter a job that makes him realize that there is a lot more to learn. Its quite a humbling experience when it happens and I would like to share with you one of my own “humbling experiences”.

A few months ago I was called out to an on-site repair job and I was told that the computer could not boot into Windows. Once I arrive on-site, I powered up the computer and sure enough, the computer would not boot up into Windows. The system would go through the BIOS processes without a problem, show the Windows XP boot logo and then the screen would switch off.

If the display works fine out in BIOS but then switches off when the computer gets into Windows, this is obviously going to driver problem of some sort. So, I reboot into Safe Mode so I can do something about this driver problem and the screen switched off again when it got past the Windows XP bootup logo.

I figure that if I boot the system into VGA mode it should work and sure enough, it does. At this point I am suspecting that the video card driver has become corrupt or something so I download the latest video card drivers from the manufacturers official site, remove the old drivers and install the new ones. I rebooted the computer and the screen still switches off once it gets past the XP logo.

I am beginning to think that the clients screen may be faulty because it cant handle the higher resolutions. I go out to my car and bring in my old 15 inch LCD screen that I use for testing. I rebooted the computer again and the problem still exists even on my screen.

At this point I am running out of ideas of what this problem could be. I was sure it was a driver issue because the video card obviously works because it would work fine in BIOS. When a video card fails it either displays artifacts on the screen, locks up or just fails completely which wasn’t the case here. I take off the side of the case and take look at the video card anyway even though I still believe this is a driver issue.

This is what I found. (click here for the picture)

It seems those two caps had something to do with controlling the resolutions 800×600 and above. When the video card was displaying 640×480 out in BIOS I believe these two caps weren’t being used and therefor the video card would work fine.

When Windows got past the XP boot screen, it would switch to 800×600 or above, the information would go through these two damaged capacitors and no video would be passed to the screen which makes it switch off.

I replaced the video card with an identical one, powered up computer and it worked instantly. I didn’t even need to do anything with the drivers. I just goes to show you that the problem isn’t always what it seems. I can fix 99% of the computers that come my way and I was so sure it was a driver problem but the good ol’ world of computer repair decided to throw a curve ball my way and keep my ego in check.