Dell Latitude monitor dims out shortly after bootup

I have a Dell Latitude (old, came with Windows 2000 on it) and it just recently started having monitor problems.

When I initially boot up the laptop, everything appears fine, and I can usually get into Windows without the monitor messing up. After about 3-5 minutes, the screen will dim out (NOT black out). Objects on the screen are still visible, just extremely hard to see. I basically have to restart the computer and do what I can in a 3-5 minute window before the screen dims out again.

I've already tried increasing the brightness and contrast to see if somehow those were being set to zero, but that had no effect on the monitor (decreasing those would not further black the screen either).

It feels like the monitor is going into a power-save mode or something. It can happen randomly, sometimes before Windows even finishes booting up, yet not as often. From what I can tell, it doesn't seem to be triggered by any actions I take, because it will do it regardless if I am actively using the laptop or letting it sit idle.

Has anyone ever dealt with this before or does anyone have an troubleshooting ideas? Thanks ahead of time.

 

does Dell have any power management software like Acer has it's Empowering? The dimming and stuff can be a hardware fault, but it can also be a software-caused problem. Reinstallation of this software and/or a fresh installation might help.

Also, what about if you go into the BIOS management screen - does it dim out there as well (because then it might be a hardware fault).

And does it happen when the laptop is connected to the power or when it's sitting on it's battery energy only?

 

It doesn't dim out if I sit in BIOS. The laptop is using AC power (don't have a battery, so its always AC).

I hooked another monitor up to it and that monitor does not dim out. Also, when I hit my CRT/LCD function key, it will refresh the screen on the laptop, but 10 seconds later it dims again.

I'm going to try staying in the BIOS longer to see if I didn't give it enough time.

 

What kind of options does the BIOS give you? Maybe thre're some settings for the video adapter or the monitor?

Also, do you have some light sensors? I know that some Asus models have them and they adjust the screen brightness according to the surrounding light. Maybe such a sensor has gone crazy in your laptop.