I've been having this problem where my harddrive keeps disconnecting after sitting unattended for a while. My SSD is perfectly fine but it can be annoying when my harddrive stops working while I am doing something important. I have gotten the harddrive over 8 months ago and had this problem for as long as I can remember, but just ignored it because it always fixed itself when ever I restarted my pc.
Harddrive
Other parts: Seagate Barracuda 3TB 3.5" 7200RPM Internal Hard Drive
https://pcpartpicker.com/list/jvtPcc
Harddrive
Other parts: Seagate Barracuda 3TB 3.5" 7200RPM Internal Hard Drive
https://pcpartpicker.com/list/jvtPcc