My Passport drive not recognised by iMac 2024

[Paul S4]

I have a 2024 iMac, which runs Tahoe 26.5.2

I have used a My Passport backup drive for years with my last MacMini and until recently, this current iMac 2024.

I recently bought a brand new WD my Passport for mac 2.0TB.

This seemed to work fine until a couple of weeks ago. The My Passport was not recognised by the iMac.

I then took the drive back to Currys, who replaced it under warranty for a new one.

This new one is not recognised either.

I am not a 'techie' as I know most of you are on this forum...

Does anyone know what the issue may be...?

PS I also experience my iMac screen going off at regular intervals, but it comes back immediately I hit the space bar...?

Could these issues be related ?

[Cloudy147]

Does the disk need formatting to be recognised by the Mac? I had to do this for one that I bought recently. It won’t read my old windows ones.

Screen going off will be the power saver mode. You’ll be able to turn that off in settings somewhere.