Core 2 Duo 2.33 GHz Model A1211: I replaced my internal hard drive with one from ifixit (the 7200rpm 500GB). I had preloaded ...
OK, a restore of a previous image backup to the new HD worked, it is now booting normally. Note, command-option-f-o does nothing, the boot process continues normally to the login screen. I'm running Mac OS X 10.6.2. MacBook Pro model 1211, 2.33GHz Intel Core 2 Duo, 3 GB 667 DDR2 SDRAM. Checking the Apple startup command list shows hold command-option-p-r during startup untill hearing two chimes. I held these keys and the Mac never chimed, it would repeatedly restart with a few seconds of startup before restarting again. Happily, releasing the keys allowed it to complete a normal startup with no apparent damage to the HD. So bottom line - the cmd-opt-p-r after the first successful boot of the new drive apparently corrupted the drive and required a restore. Further, I still don't have a known good procedure to reset NVRAM. Is there some detail I'm not getting? Apply the keys after the startup chime, before the chime?
Holding down Shift, will not boot, same repeated blue screen with wheel. Holding down Command-s, boots into single user mode and presents options to modify key file. I don't know how to modify said files so I entered Exit and boot continued... to black screen, then briefly blue, repeating back to black, repeat. Doesn't boot. Command-option-f-o, same result as repeated blue screen. Now have booted from previously removed HD in an external enclosure and (by holding down option during boot and selecting ext drive) will restore it's image to the internal drive.