Furuno FR-8251 Marine RADAR User Manual


 
4-1
Chapter 4
TROUBLESHOOTING
Danger!-Electrical Shock Hazard
This equipment contains high voltages which can endanger human life at several
internal circuits including a cathode ray tube (CRT) which uses several thousands
volts. Any internal adjustment, servicing and repair shall only be performed by
qualified service personnel totally familiar with electrical circuits and servicing of
the equipment. A residual charge remains in capacitors and other devices several
minutes after turning off the power. It is therefore essential to wait at least 3 min-
utes to allow residual charge to subside before accessing the inside of the equip-
ment. Special care must be taken when approaching the following parts:
Power supply circuit (Display unit and separate power supply units)
CRT circuit (Display unit)
Modulator circuit and magnetron (Antenna unit or separate transceiver unit)
Motor drive circuit (Antenna unit)
When Working on the Antenna Unit
Wear a safety belt and a hard hat when working on the antenna unit. Always make
sure that the radar is POWERED OFF and the Antenna Switch in the display unit is
OFF before working on the antenna unit. Also take all steps to ensure that the radar
will not be accidentally operated by someone else, to prevent the potential risk of
being struck by the rotating antenna and exposure to RF radiation hazards.
4.1 Simple Troubleshooting
This paragraph describes how to cure operational problems, by observing the radar picture and using
operator controls and touchpad keys without opening the display unit, antenna unit or other equipment
units.
The table below shows user-level troubleshooting procedures.
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