It does sound like a dodgy or loose sata cable .. the cable could be marginal, and after some heat slips slightly out. This leaves the PC seeing it on boot but then waits for it to respond, which it cant do. I would unlpulg all your sata cables and possibly buy new ones, and then replug them making sure they are properly routed (sometimes fans can touch them). ALso try booting with only one drive plugged . Another cmdline to try is "FIXMBR"