Humminbird 120 Fish Finder User Manual


 
MAINTENANCE AND WARRANTY
TROUBLESHOOTING
TROUBLESHOOTING
Do not attempt to repair the fishfinder yourself. There are no user serviceable parts
inside, and special tools and techniques are required for reassembly to ensure the
waterproof integrity of the housing. Repairs should be performed only by authorized
Humminbird technicians.
Many requests for repair received by Humminbird involve units that do not actually reed
repair. These units are returned “no problem found.” If you have a problem with your
Humminbird, use the following troubleshooting guide before calling Customer Support
or sending your unit in for repair. Your Humminbird fishfinder contains several tools that
can aid in determining if there is a problem and how to isolate and repair the problem in
many cases.
1. Nothing happens when I turn the unit on.
Check the power cable connection at both ends. Be sure the cable is connected
correctly to a reliable power source - red lead to positive, black lead to negative or
ground. Ensure the power available at the mount is between 10 and 20 VDC. If the unit
is wired through a fuse panel, ensure the panel is powered. Often accessory fuse
panels are controlled by a separate switch or the ignition switch. Also, often a fuse can
appear to be good when in fact it is not. Check the fuse with a tester or replace it with a
fuse known to be good.
Check the power connection to the unit. It is possible to force the power cable connector
into the cable holder incorrectly. If the connector is reversed, the unit will not work.
Examine the contacts on the back of the unit to ensure there is no corrosion. Finally,
ensure the unit is firmly seated on the mount. The electrical contacts are not made until
the unit is fully seated.
Ensure the metal cable retainer is properly installed in the mount. If not, the power
connected may push out when the unit is put on the mount.
2. There is no transducer detected.
Most Humminbird fishfinders have the ability to detect and identify that a transducer is
connected. If at power up, a message indicates "transducer not connected,” only
simulator operation is possible. First, ensure that an appropriate transducer connector is
positioned correctly in the connector holder, and that the unit is fully seated on the
mount. Your Humminbird fishfinder will work only with an appropriate transducer; check
the accessory guide for compatibility.