Issues Turning Computer On

Interesting issue.

Trying to take a look at a friend's laptop, it would turn on for a moment and immediately shut down. I decided to disconnect the battery, power cycle, and then turn it on using only the charger, which worked.

I then tried to plug the battery back in, with the charger aswell and it turned on just fine. I then took the charger out and it is back to square one.

The interesting thing is that even when the laptop dosen't have the battery plugged in, I have to power cycle it before it will turn on.

I also tried plugging the battery in WHILE the laptop was on, and then unplugged the charger, and to my surprise, it stayed on. But would not turn back on after a regular shut down.

My basic tech support skills have reached their limit, any ideas?