Scantronic 9100 fault

["Dave Partridge" <avvq64@xxxxxxxxxxxxx>]

There is a fault with the alarm.   With the system in engineering mode,
selecting 97/Enter (Engineer Walk Test), the display shows a tamper fault
with zone 4.

I have shorted zone 4 A/T loop and also zone 4 alarm loop at the panel, and
the fault persists.

My suspicion is possibly the TC4021BP shift register associated with the
zones 1 to 4, but it could be a problem with the dirving circuits.

Does recognise this fault?   Are circuit diagrams available?

Thanks
Dave