Latitude E6400 power issues, won't turn on and won't turn off...?

As random as the title is, they're the problems I'm having.

Today my Latitude E6400 was fine, I closed it and opened it a few minutes later when the screen flashed black and came back as all white. Holding down the power button then turning it back on brought back another all white screen, however I could still hear the hard drive working as it was starting up. After letting it sit without the battery and not plugged in I put the battery back in and it didn't quite turn on, the power button light started bright then went dim and kind of flickered. After a few tries I got it on, only to have it freeze up after 30 seconds or so.

After 7 hours, it turns on as soon as I put the battery in, only to turn back off and go to the dim flickering power light. The difference now is I can turn it on, but not off again. Trying to go to shut down, restart, suspend to ram (sleep or standby) or suspend to disk (hibernate) results in it going to a black screen and doing absolutely nothing. I also noticed that it's draining the battery insanely fast, I normally get two and a half hours off a battery but it dropped to 54% in 20 minutes. Closing the screen also results in the flickering powerlight, black screen despite the fact that Windows is set to do nothing with the screen closed.

I already cleared the CMOS on it (removed internal battery, waited) and tried with only power cord, same problem only after I removed the battery it complained about the date and time. So far it's been running without a lockup.

So, is this here an odd problem only I have and will probably require a new motherboard, or is there something I'm missing that would be causing this?