Why won't it turn on despite battery life or plugin?

I'm honestly not sure if what type of ThinkPad it is, doesn't really say on the unit, though it was new enough that it was able to use the Windows XP I put on it. Anyways I've had this computer for a while now, hasn't worked in 3 years give or take. I press the power button and a light comes on and it makes a noise like its wants to start, then it doesn't. Screen doesn't come on or anything. It seems like a "false start" if you will. How can I fix this? Even a temporary fix so I can get files off of it would be fine.