|If it was a Virus it would at least POST (boot to a black screen with white letters and do the testing). If it does not stay on long enough to do a POST then it is a hardware issue and no a Virus did not do this. |
To check your RAM there should be a panel under the computer you open to get to the RAM. Some computers have it under the keyboard. It could also be a CPU issue if the Fan is clogged. You may want to blow it out with canned air.
Another thing it could be is your power pack has gone bad and it is no longer charging the battery. If this is the case you will need to get another one.
It could also be (I hope not) the power regulator in the laptop. If this is the case then you will need a new motherboard.
If you are not comfortable with this then take it to a repair shop.