It's been a while since I posted. I've started working with the 2011 i5 models recently and noticed that many seem to come my way that have the same issue: when power is supplied to the board the fan spins and else nothing happens (chime, POST, etc) or the fan spins and then stops and then spins and then stops. I know that usually once power is given to the board through AC and battery, the i5s tend to startup on their own, but I have come across any Core 2 Duo models that exhibit the spin and stop, spin and stop issue. Have you had any luck figuring out what could be going on with these boards?
As always, that you for your insights and expertise.