Hello. My Toshiba Satellite C55-A5300 was dropped. Shortly thereafter the laptop shut down. Upon restart, I got the message checking media-failed -no bootable device found, etc. etc. I have tried 3 different hard drives and none were recognized. I have tried every remedy I could find; power/f12 and disabled secure boot, power/0 (zero), f8/shift/power, disconnected from power source, removed battery and hard drive and CMOS battery then reconnected-still same message. Made sure all the connections were secure. What else can I do? I am beginning to think it is a Motherboard problem and if so, is it worth the time and expense? I might add that I am using Windows 8 OS and I do not have recovery media.