My laptop has a white screen and when I turn it on, I comes on then goes right back off. Then it will come back on again for maybe 30 seconds. The fan comes on and it seems like it's working but then shuts off. I have done the battery thing and trying to start it without the battery, on the plug. No go. It was working and I checked to see if an external monitor would work and it did. On of these things said to fix the screen take the battery out and unplug, etc, etc. Which I did. Now it won't boot. Please help me, I'm an online student and can't afford a new computer.