Hi all, I have a 2010 MacBook Pro with some really strange behavior. Trying to start it, it hung on a white screen forever. I ran apple hardware test, both the short and long test, and that came up with no errors. I replaced the hard drive with a spare, and then disconnected the hard drive flex cable (expecting that to be bad.) Reset the PRAM and SMC. Tried to boot with network restore, it downloaded the boot data and seemed like it would come up, but once the spinning globe went away, the screen flashed and went white indefinitely again. Both with the HD flex cable connected and not. I haven't managed to get anywhere. I took the hard drive out and put it in an enclosure. It clicked and wouldn't start. Tapped on it a few times and it spun up and worked fine, even passed first aid... So I thought it was the HD or the HD cable, but without either it still won't boot into recovery mode, or from USB or firewire target disk mode. AHT and boot option screens work fine. I'm at a total loss, do you have any ideas? Thanks in advance.