Raytheon HSB L760, Owner'S Handbook Manual

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8-4 HSB Series L755 and L760 Fishfinder
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8.3 Problem Solving
All Raytheon products are, prior to packing and shipping, subjected to
comprehensive test and quality assurance programs. However, if this unit
should develop a fault, please refer to the following table to identify the most
likely cause and the corrective action required to restore normal operation.
If you still have a problem after referring to the table below, contact your local
dealer, national distributor or Raytheon Technical Services Department for
further advice.
Always quote the product serial numbers. The display unit serial number is
printed on the back of the unit.
Common Problems and Their Solutions
Table 8-2: CommonFishfinder 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.
Fishfinder 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 Fishfinder.
Fishfinder 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.
Fishfinder display is unreliable at
high boat speeds 1. Turbulence around the transducer may be confusing the
unit.
Fishfinder displays a lot of back-
ground noise 1. Check that the gain is not set too high.
2. Check that the transducer is mounted correctly and is
clean.
Fishfinder speed or log readings are
wrong 1. Check that the transducer paddle wheel is clean.
2. If necessary add a speed offset.