My laptop is a HP Pavilion dv6500 (dv6647cl) just crashed randomly during basic internet browsing. I turned it back on and I get the Operating System Not Found error. In the BIOS I do not see the hard drive recognized. I connected the hard drive to a different computer and it is recognized and it appears as though nothing is wrong with the drive. Is it safe to say that internally the SATA controller is dead? Will edit after running diagnostics and sector tests on the drive. Any suggestions? Thanks.