The USB port is underpowered. You have to try using a better power adapter for MK808B+ or use Y cable to power your hard drive.
Thanks for your advice it seemed to have fixed it
I managed to find a 2 usb uk plug i had lying around and a y usb cable
one for the mk808b plus and other for the extra power for the hard drive
it did happen once the weird sound but after since has not happened again which is the main thing
thanks very much 
Hi sorry to disturb I install libreelec onto my mk808b plus
for the most everything works great fast boot browsing etc....
but when i plug in any of my portable usb hard drives I get a weird click / ping noises from the hard drive
it even happens to my new one and this issue never happens when i plugged in my device in my computer laptop or any other device
or even with other custom roms on mk808b plus or default fw
any solution to this? any help would be great thanks
