My Book backups - commences but doesn't finish!

hello, I have a My Book 4TB unit which has been working well for a couple of years. It recently stopped the regular backups and started to making a noise. When I start a manual backup, the pop-up screen shows that the unit is preparing backup but never progresses beyond that.

Hi @PhilD2,

Please refer below link to check WD hard drive makes a repeated clicking sound:
https://support-en.wd.com/app/answers/detail/a_id/11196

Please refer below link to check if a WD drive is damaged or defective:
https://support-en.wd.com/app/answers/detail/a_id/12452