I'm having the same problem here I think.
Upon powerup i get 10 seconds of activity, then an 'on-off-on' cycle with no progress.
connections good, power supply good (brand new jeantech jn120f-600A), all devices good (no hard drive connected yet). mother board also known to work.
i'm trying to feed power just to the motherboard alone but i still can't get a reaction other than the same cycle.
the switch you mention, where is that? it can't be the front power switch, can it?