I have a 15" late 2011 MBP with 2.2 i7 processor. I have installed an optibay drive in my computer with an SSD in it and a seperate mechanical 1TB drive for storage. The computer randomly froze one day while I was using it, turned out that the hard drive is faulty. (OCZ Vertex 2) So I replaced the SSD with a corsair one I had lying around, I tried to install OSX using an SD/USB/Internet recovery and none would install, it would take many hours to try to install and crash halfway through. I put the SSD in the OEM slot and removed the 1TB hdd, it worked and installed OSX in under 30 mins. I can't understand how to diagnose that the optibay is at fault here, as it's not exactly a complicated piece of hardware, and it seems a bit of a coincidence that both the HDD and the optibay simultaneously developed a fault. Does anyone have any experiences with a similar setup?