Cant Backup iPhone 6 plus

[Macnificant]

I have been trying to back up my 6 Plus to iTunes for the last fews weeks with it plugged into my iMac and I keep getting cannot back up phone because it was disconnected.

I have trying different usb cables, ports and a usb hub not it keeps saying disconnected.

Can anyone help out

 

[bandofbrothers]

Have you tried Dfu mode or Recovery mode ?

Perhaps an Apple Store can help.