Accenta G4 mini and remote keypad only illuminating?

I recently had an issue with my Accenta G4 alarm and remote keypad. For some unknown reason the tampers were all not wired in the main box and thus not wired into the panel. I have linked all the tamper circuit wires correctly and placed the last 2 wires into the TAM onto the main panel and added an extra PIR into an extension room. The issue now is the remote keypad is only illuminating the numbers or rather the top LEDS are illuminating and No power LED or unset LED is illuminated in fact none of the bottom four LEDS illuminate at all. I cannot do anything with it i.e. put in a set code or enter engineers mode. I have tried a spare Accenta remote keypad, to no avail (after powering down the system). If I power down and remove the battery terminal and main live supply for a number of seconds or minutes it powers up and again no LEDS are illuminated on the keypad. Although the outside SAB works until power is reapplied. I have tried the factory reset as per the manual but this will not do anything ( I'm assuming I'm carrying this out correctly as per the manual power down, put a link wire into the SET terminal on the bottom row, and the put the other end into left hand side of the PA terminal after removing the link. For information I have 13.5VDC at the output in the main panel and 13.5VDC at the remote keypad +VE & 0V terminals, all fuses are intact in the main panel and the battery seems fine, 11.8VDC (it is an Ultracell 12v 2.4AH/20hour battery). The transformer is outputting 13.8VDC so charging voltage is ok. Can anyone help with this issue. I must say the alarm has been working fine until a PIR was added to the system, but if I take this out of the equation it doesn't help or change anything.

Many thanks in advance.

Rich.