Julian Coleman <jdc@coris.demon.co.uk>  wrote:
 > > I recently dusted off my SS10 which I haven't turned on in a month or two, but it wouldn't boot. I switched it on and off again a few times, and after about 10 minutes or so of not booting, the
 > > monitor switched on, the floppy tested itself and the PROM messages came up on the screen & the thing booted as if nothing had happened.


I watched this same thing happen on my SS10 when I'd switch CPU's from the
old 40Mhz to a Ross 100Mhz hypersparc.  Turn it on and it'd sit dead like dinner
for 10-15 minutes and then boot happily.  Later I'd switch back to the 40
and run it for a while, only to put the 100 back in a few months later, again,
same 10-15 minute delay.

No idea what it was doing or what caused it.  Also not saying this is what's
happening in your case, but this might help you as a datapoint.