I seem to have an intermittent issue whereby my MacBook Pro seems to lose all connection to my main drive. If this happens when using the MacBook the whole thing obviously completely locks up. It takes me multiple attempts to boot in when this is happening, I quite often get the screen with a folder and question mark. This issue is intermittent and I can go days at a time with it working fine, the issue seems to be more regular when moving the MacBook around or using it on my lap, which is why I suspect it to be a loose or damaged connection to the drive maybe, rather than a total drive failure. I'm having real trouble getting Apple to accept there is a hardware fault, as each time i've taken it in the issue has not been present. Would really appreciate some advice on how to approach this with Apple as I don't live close to an Apple Store and its a major inconvenience having to keep returning. I have spoken to Apple support on the phone and after 2 hours of tedious resets/reboots etc they finally accepted it is probably hardware related and recommended I made genius appointment, only problem is my Apple Store NEVER has available Mac appointments. I've finally managed to get an appointment booked in by going into the store and making a little bit of a fuss, but its a fortnight away. I'd really appreciate some insight into what the issue might be and advice from people used to dealing with Apple in the best way to present the situation/evidence to them when I go in for my appointment. I have the following two screenshots showing the screen I often get when trying to boot, and the Drive Utility Application in recovery mode showing no main drive present when I attempted to reinstall OSX as recommended by the phone support guy. (I have since tried a clean OSX install just to humour them and it did not resolve the issue in any way). (Yes I know my screen needs a good clean) No drive!! After a few more reboots it eventually 'found' it and booted in successfully. This is a recurring issue.