You might have damaged your USB ports
I recently dropped my 1TB HDD on the floor which resulted in it being damaged
irreversibly it made noise then seized to function thus losing 350GB of
invaluable data.i could not transfer any of its data via usb other HD or even
LiveCD.trying to replaced the head resulted in scratching the disk and losing
the second HDD of 500GB
https://en.wikipedia.org/wiki/Hard_disk_drive
if your USB port is damaged you may also have insufficient power Voltage to
properly read the ext Hdd
By the way that video is of no help it only shows how to dismantle an
Inclosure
check in your
# grep -i error /var/system/log/messages
that will tell you if you have insufficient or erratic reading due to power
shortage
to see if your USB ext HDD is detected
lsbusb
dmesg
