I've finally gotten round to putting the recessed door contact (Knight A51MULTI G2) for the entry/exit rather than using the hallway PIR.
I wired everything up and re-enabled zone 1 but it was displaying tamper. So I stripped back the contact and tested all the resistances 2.2 secure, 6.9 active, 1/0 tamper. I also checked the resistances at the alarm box to make sure I didn't have a break in the cable.
To confirm I linked the contact circuit into Zone 6 which was spare and wintex diagnostics registers 2.2 secure (healthy).
Finally to confirm Zone 1 I bridged and programmed zone 1 to always closed which returned an active state (unhealthy)
Does it sound like Zone 1 is dead and I need to replace the board or could it be a common faults that can be rectified without a board replacement?