will not power on?

I press the power button and the blue power light will come on for 2 or 3 secounds and the turns off. This happened before and i unplugged it and took the battery out and replaced the battery and it turned on but after it was shut down it would not power back up. If you remove the hard drive it will power up to the screen that says the is no drive present. But this to is a fading reality. I know the hard drive is good put it in my wifes laptop no problems. So what's the fix or do i junk it?