iTunes "could not connect to the device" (iPhone to iMac)

Hi everyone,

I have been unable to backup my iPhone 5s using iTunes 12.2.1.6 and it displays the above error message (see screenshot also).

Both my iMac (OS X Yosemite 10.10.4) and iPhone softwares are up to date. I have rebooted both devices. Rebooted the iMac twice, once with the iPhone plugged in and once without. iCloud is successfully setup on both devices using the same account.

Also interesting that the error message doesn't say "this iPhone" as it does for some users on this forum—does it not recognize what it is? Meanwhile, I can access my iPhone photos from the iMac using iCloud, so it seems to be strictly an iTunes issue.

I'm running out of ideas! Any help is appreciated.

Thanks

Louisa

EDIT: The problem was that I was using my belkin cable instead of the original Apple one. It works fine with the latter.

EDIT

Message was edited by: louisa_b