Is a new SATA cable for that drive and change to another power cable from the PSU.
I have a one year old PC and for the past couple of days I have had an issue. I have two interal drives, one SSD where I have the OS, and one WD HDD. The HDD keeps disconnecting at random times and then reconnects after a few seconds. I've chekced the SATA cables, they are properly connected. I can't figure out what might be causing this. Any suggestions? Thanks!