Humminbird 300TX manual

To use the Diagnostic feature, select the Diagnostic feature on the start-up menu on the initial screen. Diagnostic can also be accessed through the Options menu.

Self Test. Initially, the 300TX will perform a self-test. This test confirms the operation of all internal circuitry. At the conclusion of the test, one of two messages will appear. “Passed” indicates the internal test discovered no failures, “Failed” indicates a significant internal problem was discovered and the unit requires factory service. A code number appears that tells repair personnel where the problem is.

Transducer Connection. The first connection tested is Transducer input. If a transducer is detected, the message “connected” appears. If a series of dashed lines is shown, no transducer is connected or there is a problem with the transducer or cable.

If you are using multiple transducers, switch between transducers to confirm the connections for each.

Boat Speed/Water Temperature Connection. Other connections tested include the boat speed and surface water temperature sensors. These accessory sensors can be purchased independently or together as a single sensor (see the Humminbird Accessories catalog). If the sensors are connected and working properly, a “connected” message appears.

The speed input feature only works when the boat is in motion as the paddle wheel on the speed sensor must rotate to be detected.

Voltage Input. Another connection tested is the voltage input, and is especially helpful in diagnosing input voltage problems. The current input voltage is displayed. If voltage fluctuations or power supply in excess of 20 VDC or less than 10 VDC is suspected, use the diagnostic screen to confirm input voltage. Often, small outboard motors do not effectively regulate voltage when operated at high engine speeds.

Use Diagnostic while running the boat at high speeds to show the voltage gain. Also, if you are using the 300TX in portable configuration or from the trolling motor battery, Diagnostic screen to confirm input voltage when operated at high engine speeds.

Use Diagnostic while running the boat at high speeds to show the voltage gain. Also, if you are using the 300TX in portable configuration or from the trolling motor battery,