My unit is not properly depicting fish. What should I check?

Shows Few or No Fish
Consult the Common Checks guide and make sure that all categories are fully verified.
Fish Symbols vs. Pixels

Not all models of depth sounder will show a fish symbol for targets that are detected. Some will only show them with a pixel or a group of pixels. Some models of fishfinders have the option to show detected targets as fish symbols or the raw sonar data. Consult your Operations Manual for your depth sounder capabilities.

Check for Simulator ModeCheck that your depth sounder is not in simulator. With the depth sounder turned off, momentarily press the power button. Normally you should hear one chirp if the depth sounder is turned on in normal operation and multiple chirps if the depth sounder is turned on in simulator. Some models will flash or scroll the word "Simulator" on the display.

Features and MenusFor those depth sounder with the following features and menus, try adjusting them as stated:
        * Sensitivity - adjust all Sensitivity menus to a higher setting.
        * Gain - increase this setting.
        * Fish ID Adjust - increase this setting.
        * (Noise) Filter - turn the filter OFF.
        * Transmit (X-Mit) Length - increase this setting.
        * Transmit (X-Mit) Power - increase this setting.
        * Beam - turn all transducer beams on.
        * Water Type - set to present water type.
        * Surface Clutter - adjust so that less surface clutter is blocked.
        * Turn off any other depth sounders
        * Bottom View - adjust to Inverse (Grayscale) so that weaker signals will be easier to see on the display.

Check the Transducer* Check the Operations Manual and Transducer cable for the proper transducer. Normally, the transducer type is marked on the cable within the first 6 inches from the connector end. The correct transducers to be used with your unit are listed in your Operations Manual.
* Check for proper transducer installation, according to the Operations Manual. If the transducer was installed to "shoot through" the boat hull, the installation may have degraded allowing air bubbles to be trapped between the transducer and boat hull. It may be possible to check for this by adding enough water to the boat hull to partially cover the transducer. The water may displace the trapped air and allow the transducer to work properly. If this happens, the only long-term solution is to try and remount another transducer in your boat's hull.
* Check for Marine growth or other obstructions that may be on the bottom of the transducer. Some Anti-fouling paints may not be used or may only be used in a single thin coating. Clean the bottom of the transducer with soap or detergent and water or lightly sand with sanding paper. This will help "wet" the transducer. When putting a transducer in the water, it may form air bubbles across the face or "eye". This can be simply rubbed away with your hand. Older model transducers have to be allowed to wet before they will work properly.

Fish VariablesThe size of a fish's air bladder helps determine the size fish displayed. There are many variables that affect this, some of which are:

* The species of the fish. You may be over a large fish such as a flounder, however because it has a small air bladder and according to your fishfinders settings, it may be displayed as a small fish or not at all.
* Whether the fish passed directly under the transducer or off to a side. If a large fish were to pass to one side of the transducer, its air bladder may not be fully in the transducer cone angle. This will cause a much weaker return signal to be reflected back to the depth sounder. A weak return signal could be displayed as a small fish or as baitfish or due to various settings on the depth sounder, not at all. If the same fish were to pass directly under the transducer, it could be displayed as a large fish.

Customer Resource Center
If you are still having problems after trying the preceding suggestions, return your depth sounder along with the power cable, transducer(s) and any accessories (switches, temp, speed, etc.) and a letter with a detailed description of your problems to:

Johnson Outdoors Marine Electronics
Service Department
678 Humminbird Lane
Eufaula, AL 36027

(800) 633-1468 Customer Resource Center
email: service@humminbird.com