Humminbird 955C Finding the Cause of Noise, Year Limited Warranty, Away from the engine wiring

531569-1_B - 955c ManE.qxp 3/4/2007 5:04 PM Page 81

Finding the Cause of Noise

Electrical noise usually affects the display with many black dots at high speeds, and high sensitivity readings. One or more of the following sources can cause noise or interference:

Possible Source of Noise Isolation

Other electronic devices Turn off any nearby electronic devices to see if the problem goes away, then turn them on one at a time to see if the noise re-appears.

The boat’s engine	To determine whether the boat’s engine is
	the source of the noise, increase the
	RPMs while the boat is in neutral and
	stationary to see if the noise increases
	proportionately; if noise appears when
	you rev the engine, the problem could be
	the spark plugs, alternator, or tachometer
	wiring. Replace the spark plugs with
	resistor plugs, install an alternator filter,
	or route the control head power cable
	away from the engine wiring.

1-Year Limited Warranty

We warrant the original retail purchaser that products made by Humminbird® have been manufactured free from defects in materials and workmanship. This warranty is effective for one year from the date of original retail purchase. Humminbird® products found to be defective and covered by this warranty will be replaced or repaired free of charge at Humminbird’s option and returned to the customer freight prepaid. Humminbird’s sole responsibility under this warranty is limited to the repair or replacement of a product that has been deemed defective by Humminbird®. Humminbird® is not responsible for charges connected with the removal of such product or reinstallation of replaced or repaired parts.

This warranty does not apply to a product that has been:

•Improperly installed;

•Used in an installation other than that recommended in the product installation and operation instructions;

•Damaged or has failed because of an accident or abnormal operation;

•Repaired or modified by entities other than Humminbird®.

Please retain your original receipt as a proof of the purchase date. This will be required for in-warranty service.

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