Raymarine L470 The display unit does not see the bottom or fish, Maintenance and Troubleshooting

4.The transducer cable may be damaged. Check for any point where the wiring may be pinched or bent. Look for signs that water has gotten into the cable. If the transducer cable is damaged, the transducer and cable should be replaced as a unit. Contact Raymarine for instructions.

The display unit does not see the bottom or fish –

1.Be sure the display unit is not using the Simulation mode (If this is the case, the word “Simulation” will flash on the display.)

2.On a unit with the transom-mount transducer, the transducer may have “kicked up” because it hit an obstruction. See Fig. 2-4. Move the transducer down into the working position.

3.The unit may be set for Manual sensitivity, and be using a very low sensitivity setting. To reset all of the values to the factory defaults, hold the CLEAR button, and press PWR to turn the unit on. See the default settings on page 82.

4.The transducer may not be vertical. Be sure that the transducer is aiming straight down, or within 10° of vertical.

5.If the transducer is an in-hull type, be sure that it is installed correctly. The transducer should be “looking” through just one layer of fiber- glass hull material, no more than 1" (25 mm) thick. The transducer should be firmly attached to the hull using the correct type of adhe- sive/sealant.

6.The face of the transducer may be covered or fouled. Use a stiff brush to clean it. You may also sand the surface with a fine-grit wet or dry sandpaper (#320 grade or finer), but this will affect the perfor- mance of the unit when the boat is moving at higher speeds.

7.If the FishFinder is using the Auto Sensitivity setting, it may be reacting to an increase in electrical “noise.” As the level of noise increases, the sensitivity automatically adjusts, and the unit can lose its ability to see the bottom or fish. Check for problems with the wiring as described in the section on “Display unit freezes.”

8.The voltage from the power source may be low. This affects the transmitting power of the FishFinder. Check the connections as described in the section on “The display unit freezes.”

The FishFinder does not display fish arches –

1.Be sure the Fish Symbol feature is turned off. See the instruc-

Maintenance and Troubleshooting 85