2008 White MacBook random rebooting

I've been having a lot of issues with my late 2008 white macbook 13" 2.1 2GB RAM and 160GB HDD. when you plug in a magsafe charger the light comes on green but DIM. and it doesn't want to turn on. If i let it sit for a while i can eventualy get it to boot, but the fans run at a rediculous speed. If I am lucky enough to the Lion installer It begins to install but then randomly reboots. It reboots from everything, the original Leopard DVD, the Snow Leopard DVD, and my Lion USB. When it did boot from the hard drive it would sit there for a while, but then it would shows the reboot dialogue asking if i want to restart then just turns off, the other methoods are just sudden reboots. Ive run the self test by booting with D, and it passes with no errors found. But this issue seems to continue, Ive read that it could be dirty RAM modules, so i took them out to clean them, although te WERE dirty that did not solve the issue. Ive heard of it beign a bad hard drive, but i cant see how that would cause the issue. Ive reset the PRAM by holding command+option+p+r but that does nothing. I've held the power button for 5-seconds without the battery or charger, and I've pretty much out of options. I just want to have my laptop back, someone please help. 😟