Hello eveyone, I'm hoping to fix my brothers macbook pro 5,3 (2,53Ghz 15" mid 2009). The machine didn't work anymore after coming back from sleep, it froze so he did a hard shut down. I tried everything to recover, after that to reinstall, but the hard disk didn't do everything as it should. when i tried in single user mode, i couldn't get to the 'terminal'. I was unable to format using disk utility, the disk wouldn't unmount, etc. it looked to me the disk was broken. I have an external casing with data disk in it on with i installed os X lion. works great, no issues. And (to me) surprisingly fast over a single usb port. But when i now try to put that disk in the macbook pro, it doesn't work. there was the blinking question mark on the folder, so i tried some other things, and sometimes when i now boot the external working disk on usb, and leave the original disk in, it is getting recognized. but it freezes when i try to anything with it. the external disk is a western digital blue 500. and now i thought maybe the EFI was outdated, but when i download from the apple page, it won't upgrade because it isn't the right version. when i look to system profiler it states the macbook is a 5,4... any thoughts? i'm getting lost on this one, can the data cable be broken? or the motherboard in such a way that it actually works, only not the hdd data connection? thanks!