Karlos wrote:
3) Ropey timing issues (not uncommon for older Apollos) -
trickier to diagnose and fix, but usually this prevents the system from starting at all, so with any luck it isn't this.
Well, as he says in a later post it sometimes crashes on the insert disk screen.
Ian Stedman has a very helpful page covering the fixes needed for the various A1200 revisions.
http://www.ianstedman.co.uk/Amiga/amiga_hacks/A1200_Mobo_fix/body_a1200_mobo_fix.html