I have a Compaq Presario 2500. While I was using it yesterday my mom came in and asked me to run over to the farmstand and get an apple pie for after dinner. I went out, wasn't gone for more than 25 minutes, and came back to find that the laptop I left on was now turned off. I couldn't get it back on. First I thought it was something funny with the power cable. I'm using a Targus cable instead of the one the laptop came with. I noticed the blue light on the Targus cable wasn't going on when I plugged it in again. Then I realized, though, that if I unplugged the cable on the laptop end and just plugged it in at the wall socket the blue light does come on but as soon as I plug it in to the laptop the light goes out. This just seems like a funky cable problem but here's what gets me worried: the battery in the laptop still shows it is powered but it is still completely dead when I press the power button. What kind of problem am I looking at here? I'm not sure if I should investigate the cable or if some kind of glitch screwed up my whole laptop in that 25 minutes of time I was out getting the pie. I have no clue- HELP!

This is kind of tricky to explain, but I'll try my best to explain it as clearly as possible. For some reason, probably to protect the computer, the power pack automatically goes off if either end shouldcome unplugged. What you have to do is plug the wall end in first. Then, take the cord that goes from the pack to the laptop and plug in the end that goes into the pack first. At this point you should still have the blue light. Finally plug the other end of this cord into the laptop, and you should be ok.

No, I've already considered that! What's happening is I can get through the steps you described until the part where I plug it into my laptop- THAT'S when the blue light goes off and no power is supplied to the computer.... Do you know of any ways I might go about getting this fixed or any resources online that might tell me why the computer is acting this way?

Disconnect the mains and remove the battery (and everything else you have connected).

Try powering from mains only with the battery out.

If that doesn't work then you know that something's broken and you can move forward from there.

The next step is to find out if it is the adapter, the laptop, or both. Since your machine appears powered on battery only but doesn't do anything, the laptop certainly seems to be implicated. But make sure you get the adapter tested because it could have been that failing which took out the laptop if there is a fault.

Try the battery reset thing first if you haven't already. I've had situations which on the outside look exactly like this but a simple battery-out-battery-in fixes it. Not always, but sometimes...