62 RAYDATA Installation and Operation Handbook7.2 Fault FindingAll Raymarine products are, prior to packing and shipping, subjected tocomprehensive test and quality assurance programs. However, if afault arises with your RayData, the following table will help you to identifythe probable cause and provide the most likely cure.Fault Cause ActionInstrument display blank. No supply voltage. Check DC power supply to RayData.Check cabling and security ofSeaTalk connectors.Check fuse/breaker.Return unit for repair.No depth or speed/temp Mode set incorrectly. If repeating SeaTalk data, changedata on RayData. mode from Master to Repeater insetup (see Chapter 4).If repeating NMEA data, changemode from Repeater to Master.No speed or temperature Speed transducer Check cabling and security ofinformation. cabling problem. speed transducer connector.No speed through water Paddlewheel fouled. Clean paddlewheel.information. Use Speed Over Ground display (ifavailable) in interim.No depth information. Depth transducer Check cabling and security ofcabling problem. depth transducer connector.No NMEA data. NMEA cabling Check cabling and security ofproblem. NMEA connector.No exchange of SeaTalk cabling Check security of SeaTalkinformation between problem. connectors.SeaTalk instruments. Disconnect instruments one by oneto isolate faulty unit.Failure of a group of SeaTalk cabling or Check security of SeaTalkinstruments in SeaTalk connector problem. connectors and non-functioning units.chain.Operation in Very Shallow WaterThe Raydata is designed to operate down to a minimum depth of 2.8feet below the transducer. Below this value, multiple echoes cansometimes be received, resulting in deeper depth readings than theactual depth.7.3 Absent DataIf a required data value is not received via the SeaTalk bus or NMEAconnection for 30 seconds, then the displays that require the data