Replacement Of Internal Battery; Testing The Underwater Unit - Furuno TS-331A Operator's Manual

7. MAINTENANCE & TROUBLESHOOTING
7.3

Replacement of Internal Battery

A lithium battery on the Mother Board inside the Surface Processor Unit
preserves settings when the power is off. When the voltage of the battery is low,
the date and time will be wrong. When this happens, have a qualified technician
replace the battery, at your earliest convenience. Install the correct battery
properly (with correct polarity). Explosion may result if the wrong battery
type is used or the correct battery is installed improperly. Dispose of the
battery according to the appropriate regulations.
Part
Lithium Battery
7.4

Testing the Underwater Unit

If you feel the underwater unit is not functioning properly, conduct the test below
to check it for proper operation, using the test cable (supplied). Note that the test
may be conducted in air.
Required parts
• Test cable (supplied)
• Silicone spray
1. Turn off the Surface Processor Unit.
2. Open the underwater unit by unfastening six screws.
48
Type Code No.
CR2032 000-129-884
Unfasten six screws
(three more on opposite side)
Underwater unit
Vertical Sonar
Transducer