Power cut set alarm off. entering user code switched alarm off as expected. But when setting alarm later alarm activated and was unable to switch off by entering user code. Only way I could deactivate alarm was by switching off mains supply to alarm. Have now reset to factory settings all tests OK Except walk test. which gives high sounder volume not low as before and does not appear to be sensing my PIR's.when I attempt to switch alarm on by user code it goes into what appears to be Walk Test sounder low volume and sensing all PIR's I can return to day mode from here by entering user code. completly at a loss tried all I can think of> any Help welcome Regards Gary