Hi Harry, Yes, one of the very first things I tried was resetting PRAM and NVRAM, including pressing the CUDA button. It's possible that such a reset might be the cause of the failure to boot, per John's previous email... I'll try to reinstall the firmware upgrade (if I can find it) and see if that fixes things. Thanks. --- Amir On Thu, 23 Feb 2012, Harry A. Freeman wrote: > Greetings, > > Have you reset PRAM and NVRAM. Also removeing the PRAM battery for 5 minutes > and then depressing the PMU (CUDA) button. The PMU button is usually next to > the PRAM battery. > > Cheers > > Harry > San Jose, Ca