Latitude e5420 Trackpointer not working

I am lucky enough to own an e5420 (i7) which has had a few upgrades (memory, SSD) that I use as a backup to my main PC for music production. I recently replaced the keyboard (which was the un-illumanted version) with an illuminated one. The new keyboard also has the trackpointer (between the B,G and H keys).

Everything works fine (keys and illumination) EXCEPT the trackpointer. I have checked in the bios, removed and reinstalled the touchpad drivers (the option to enable/disable trackpoint is there in the touchpad config but enabling or disabling does nothing), checked the ribbon connection.. I am at a total loss. The old keyboard didnt have a Trackpointer so if it doesnt work its no great loss (mainly purchased the replacement keyboard to get an illuminated one) but my OCD is kicking in because it isn't working!

Is there anything I have missed or should check?