Discovery central locking AND immobiliser

This sounds similar to other posts but not quite the same.
Having gained entry to the car I was unable to start (red immobiliser light came on). The remote key fob was unable to reset, in fact it stopped opening and closing the locks as well. Replaced the battery - no different. By using the manual process (key in lock and security code) the alarm is disabled and I can start and drive off. Manually locking and unlocking the car then requires me to go back through the manual alarm reset sequence with the key in lock and security code etc.
I would have suspected the "Spider" but with the remote central locking not working either - is it the fob or the sensor or what?
Can anyone give me a simple fault determination process to follow please?

Hi James,

Mine did exactly the same, what happened to mine is the sensor that is pressed down on the fob had broken inside, when i shook it i could hear it rattling inside.
Have you taken the fob apart to see if anything is broken or loose?
I had a spare fob so i was ok, but i just glued the broken bit back on in the other fob.

Archie

Thanks for the reply. I took it apart to replace the battery and checked out the printed cicuit. The small (yellow) press switches appear to work - at least they "click". Nothing obviously broken. Sadly no spare for me.

Not sure what else to say James, unless you get a new fob but i think there a bit pricey.

Sorry about that mate

Archie