Why is external hdd self-reconnecting?

Question

Programming

Approximately every few hours, the external hard drive reconnects, which causes the program and everything connected with it to turn off or give an error, what could be the matter? win8.1

Answer 1

Is there an option in power settings to "turn off HDD when idle"?
Some kind of power-saving feature?

Answer 2

for example, a hardware problem - a contact in the x-th or software connectors - the driver is buggy.
study the logs, wrap them with adhesive tape ... by the method of scientific poke, you can decide.
with such a detailed question, only psychics will help, but the only problem is that they all ran away to RENTV ...