My Book Essential cuts in and out

I have two 1TB My Book Essential drives. They often disconnect themselves from my laptop, stopping any on-going jobs. Particulars – brand new HP Envy laptop, 8GB ram, 2.6 3rd generation i5 processor, 3 USB 3.0 ports.

Cables are brand new.

More info: Moving the drives to another pc/laptop has no beneficial effect.

WIthout moving or touching anything, the drives can drop off. Sometimes they re-connect. Sometimes I pull the USB cabkle from the laptop, wait a bit and then re-insert.

Thoughts?

Be sure to always safely eject the My Book before disconnecting the USB cable, since this may cause data corruption and unstable performance. You can try running a test using DLG to verify if the hard drive has any hardware problem. Check the link below for the steps. 

http://wdc.custhelp.com/app/answers/detail/a_id/940

http://wdc.custhelp.com/app/answers/detail/a_id/5316