Raymarine DSM250, Owner'S Handbook Manual

Page: 109 / 122

Chapter 7: Maintenance and Problem Solving 7-5
Common Problems and Their Solutions
Table 7-2: Common Sounder Problems
Problem Correction
Display does not function 1. Make sure that the power supply cable is sound
and that all connections are tight and free from
corrosion.
2. Check the system fuse.
Display “freezes” 1. Check the scroll speed is not set to zero.
2. Check the transducer cable for damage.
If damaged, the cable and transducer must be
replaced as a unit.
Sounder does not display
fish 1. Fish arches are not displayed if the boat is stopped -
fish appear on the display as straight line.
2. Ensure the transducer is within 10 ° of vertical.
3. Check that the gain is not set too low.
Sounder does not see
bottom or fish 1. If you have a transom-mount transducer, check
that the transducer hasn’t kicked-up on hitting an
object.
2. Check that the gain is not set too low.
3. Check that the transducer is within 10° of vertical.
4. Check that the transducer face is not covered or
fouled. If necessary clean the transducer.
5. Check the voltage from the power source; if this is
too low it can affect the transmitting power of the
sounder.
Sonar display is unreli-
able at high boat speeds 1. Turbulence around the transducer may be confus-
ing the unit.
Sounder displays a lot of
background noise 1. Check that the gain is not set too high.
2. Check that the transducer is mounted correctly and
is clean.
Sounder speed or log
readings are wrong 1. Check that the transducer paddle wheel is clean.
2. If necessary add a speed offset.
3. If receiving SeaTalk speed, unplug the SeaTalk con-
nector.
Sounder temperature
readings are wrong 1. If necessary, adjust the TEMP CALIBRATE parame-
ter.
2. If receiving SeaTalk temperature, unplug the
SeaTalk connector.