Amiga 500 intermittently reboots for no reason!

[TjLaZer]

Check the belly of the 500 and see if there is a RAM card in there.  Some have NiCad batteries that have surely leaked by now and done their deed so remove it and see if it helps cure the problem...

[TjLaZer]

I would unplug the keyboard and use it for a while to see if it is indeed the KB that is causing the reboots...

[TjLaZer]

Have you tried running the 500 WITHOUT the keyboard plugged in?  (The actual thing you type on, not the computer itself!)  Yes you can run the Amiga without the keyboard plugged in.  Test to see if it does it's reboot thing...  You can buy a keyboard for CHEAP,  Just bought one NEW for $10 last month.

[TjLaZer]

Where else, eBay!  They are on there all the time.

[TjLaZer]

Header = pins sticking up from PCB.