Your RF5xx Transmitter displays message ‘ErrOr 004’ on the LCD screen, similar to that shown here. This code is only seen on RF5xx Transmitters with Firmware Version 2.4.2 or lower.
This ‘ErrOr 004’ relates to an issue with the Radio Module of the device.
Unfortunately this is not generally a user repairable fault. You could initially try removing the battery from the Transmitter, waiting one minute and then replacing it. If the ‘Fault’ persists, then the Transmitter(s) in question will need to be returned to our Service Department for repair.
Please click here for a copy of the Service Form which you will need to complete and include with any Transmitter(s) that you wish to return to the Service Department of Comark Instruments.