10 NAVMAN D100 User Manual
Troubleshooting Chart
No display:
Check DC power connections and DC polarity with voltmeter. Voltage
must be between 10.7 and 16.6 volts.
No depth reading (--) at all depths:
1. Check transducer for growth or multiple coats of paint.
2. Check the transducer cable for cuts and sharp bends.
3. Substitute the transducer with a known good transducer hold it over the
side of the boat into the water and see if instrument functions. This
isolates cause of problem (transducer or instrument).
Erratic readings (while moored):
Check transducer for growth or multiple coats of paint.
Erratic readings (while underway):
Cavitation (air) under the face of the transducer. Review installation
and reinstall if necessary.
When power is applied, display right-hand digit counts up or down:
See previous section on Depth Simulation.
Erratic readings when engine is running:
1. Reroute power and transducer cables away from ignition wires and
battery cables.
2. Add feed-through filter capacitor on the positive terminal of the ignition
coil.
3. Add alternator whine filter to alternator.
4. Replace spark plug wire with resistive type.
Simulation Mode
At power up, if all the segments display for 5 seconds then the instrument
is in simulation mode.
