Laptop power problem :\.

[justin121121]

I just recently purchased a compaq evo n620c off of ebay, which was supposed to be in working condition but its far from it.

My problem is, whenever i start up the laptop, it will power up for a split second, then turn right off.
The strange thing is, it keeps trying to boot up, and it will until you manually turn it off.

I think it is just the battery, but even when you use the a.c. plug, it does the same thing! which is really puzzling to me.

So if anyone could give me some advice, that would be very much appreciated!
Thanks!