texecom veritas constant tamper?

Hi I have replaced one of my LCD keypads due to a damaged LCD screen, (rainbow effect) ,and now the new keypad shows tamper and appears locked.

I have double checked my wiring and all seems ok but I am sure the replacement keypad has caused the tamper activation as the two already fitted are not displaying such fault.

Where have I gone wrong?.
Have I overlooked something?.
How can I remove tamper and restore keypad operation?.

Can't understand where I've gone wrong because I know it is something I have done, but I'm not seeing it.All I'm getting is tamper?.Help... I don't really want to get a pro in and look a fool so any suggestions please.

Just call me useless
December 2013