I was in the middle of extracting a rar file when my screen blacked out (it looked like my screen when the power is off). I forced restart by pressing long on the power button of my laptop but it didn't restart. The icon notifications show that the laptop is on and it is connected to the adapter.
Is there anyway I can fix this without going to the service center?
I'm using a ThinkPad R61i Ubuntu 12.04 64-bit 3.8gb RAM 160gb hard drive.