maybe worth buying the clifnet software and dongle, about 50 quid, and you can log and see what is happeneing -

mine when my concept 600 was playing up it was the wiring to the pin switch for the bonnet , a grommet hadnt been used where they had run it through the bulkhead, every time it it rained or was damp the alarm would go off, it took 10 mins to find this out with the software