My trusty old Radius 81/110 doesn't want to power down. I noticed a few weeks back it started up on its own. Took it apart and looked around, the battery is 3.6v with no leaks, capacitors looks fine (board is clean and shiny). When  a live power cable is installed to the PS the machine turns on, and even when I tell the OS to shut down the PS is still running (OS does not reboot).

So the machine works, I just cant shut it down or keep it from turning on.

Bad MB capacitors, bad PS, or something else?