Laptop Update!!!!!!!!

My lap top is pretty much toast. My brother was using it yesterday and ran into a few problems, so he turned it off. I brought it to my room and tried it. It worked for a little while, but if I leave it on for a certain about of time, the screen suddenly goes black, two little lights on the front start to flash, and the humming sound all computers make starts going a billion miles an hour, like it's going to explode or something. Not that the other problem wasn't bad, but this is worse!!!!!!!!!!!!!!!!!!!!!!!!!!!

Here's the main problem. Normally, I could afford to replace the lap top. Sure, it would make a significant dent in my savings, but the money would have gone to a good cause. Now, I'm saving my pennies to go on a trip to a huge chorale festival with my choir. I don't have the money for a lap top! The last one was a castoff from my dad's work, because it has to be hooked up all the time and you can't take it anywhere unless there's electricity, and if the slightest pressure is exerted on the plug it shuts off rather suddenly. Now this! WHAT AM I GOING TO DO??????????