Panasonic NV-GS250 won't turn on

My NV-GS250 camera will no longer turn on - no sounds, no red light, can't get the DV tape out as it doesn't seem to have power. I've tried using the mains power adapter so it's not a battery problem. Also tested the battery output. There was a bit of a rattle inside the camera like something had come loose and was moving around. I opened the camera up (a little bit - far too complex for me) and a small screw fell out (that had been loose on the inside). Do these cameras have a spare screw stored somewhere in them? I can't imagine one working loose. That's beside the point, I guess. Has anyone taken one of these apart and can tell me where to look to find a break in the power circuit? I don't believe the switch is the problem, by the way, as the switch doesn't need to be on to open the tape compartment. There was no major trauma to the camera for this to occur. It hadn't been dropped or anything. Cheers