It happened to me a couple of days ago. I tried to plug in my external hdd and it wouldn't show up. The hdd is a western digital. I tried all my USB ports and I tried 2-3 USB connections and non worked. When I connect it I see the driver get installed but it takes about 2-3 min. to install and it still won't show up on device manager or on My Computer. I opened the case and connected the hdd as a slave to my motherboard but when I went into the BIOS to Auto-Detect it, nothing i came across this (refer to video):
It fell off my dresser which is 2 1/2 feet tall. I just hope that the arm inside didn't break or something. If anybody has any experience with something like this please let me know. I have a lot of info to recover from this hdd.
As you mentioned its fallen and while connecting to system directly its not even being detected then its probable damaged internally and cannot be repaired also,try fixing it in another external hard drive enclosure and try your luck.
