Central locking not working

[Romal]

Hello new to the site looks like a pretty good site to sort out x5 issues.

Can anyone help

My central locking does not work fom the fob
the central locking button inside works but the fob wont lock the doors.
Tried reprograming the fob(no joy)
Brought the key to a guy who told me there is power coming from the fob but still does not lock.
Is there a check i can do to see if the key is ok
or is there a test to test the central locking module

Thanks in advance for your help

Romal