Insignia 450TX - Manual (Page 36)

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MAINTENANCE
TROUBLESHOOTING
6. I get gaps in the reading at high speeds.
Your transducer needs adjusting. If the transducer is transom-mounted,
there are two adjustments available to you—height, and running angle.
Make small adjustments and run the boat at high speeds to determine the
effect. It may take several tries to optimize high speed operation. This can
also be a result of air or turbulence in the transducer location caused by
rivets, ribs, etc.
7. My unit loses power at high speeds.
Your 450TX has over-voltage protection that turns the unit off when input
voltage exceeds 20 VDC. Some outboard motors do not effectively regulate
the power output of the engine’s alternator and can produce voltage in
excess of 20 volts when running at high RPMs. The 450TX displays input
voltage in the Diagnostic screen. Use this readout to determine if the
voltage exceeds 20 VDC.
8. The screen begins to fade out. Images are not as sharp as
normal.
Check the input voltage using Diagnostic. The 450TX will not operate on
input voltages below 10 VDC.
9. The display shows many black dots at high speeds and high
sensitivity settings.
You are seeing noise or interference caused by one of several sources.
Noise can be caused by other electronic devices. Turn off any nearby
electronics and see if the problem goes away. Noise can also be caused by
the engine. If engine noise is causing the interference, the problem will
intensify at higher RPMs. Increase the engine speed with the boat
stationary to isolate this cause. Propeller cavitation can appear as noise on-
screen. If the transducer is mounted too close to the propeller, the
turbulence generated can interfere with the sonar signal. Ensure that the
transducer is mounted at least 15" (38cm) from the prop.
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