Hi guys, We've got a MacBook that's not booting. It gives a question mark when we turn it on. I've tried resetting the PRAM and SMC, to no avail. I've tried booting holding Option to list all bootable volumes, and nothing is listed unless I put the install DVD in. I've booted from the restore disks, and tried to reimage the MacBook, but no volumes showed up to install to. I tried Disk Utility off the install DVD, and it listed no bootable volumes. I tried System Profiler off the install DVD, and it said "There was an error while scanning for Serial-ATA devices." Is this absolutely for sure a hardware issue? this guy seems to have solved almost the same problem without, but I'm not able to reinstall like he did (it gives me no volumes to install to). I don't have much time and need to know whether to send it in to Apple or not. Being that we're past 90 days, they won't give us tech support over the phone, so if it's not a hardware problem, we're going to get charged, and other circumstances dictate that the computer either be fixed or installed ASAP. Thanks for the help!