Chapter 4: Disassembly and Reassembly
Type 150/150G/400/400G Course Computers Service Manual 83156-1
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Type 150/400 Course Computers
Chapter 3: Functional Tests
3.1. Introduction
This section describes how to complete basic functional tests on the Course Computer
aiding fault diagnosis.
Equipment and Tools You Will Need
•
Raymarine ST6001 or ST7001 Control Head
•
Raymarine Rudder Reference
•
Raymarine Fluxgate Compass
•
Any Raymarine Pathfinder Display
•
Digital Volt Meter
•
DC Power Supply which can supply 12V and 24V (if T400’s are to be tested) at 5A
(to cope with inrush currents when motors are started during testing)
•
A 12V Mabutshi motor
•
A Raymarine type 1 motor can be used for this purpose, but will require a larger
PSU (10A) to cope with the inrush during start up.
•
A conventional 330 Ohm resistor, rated at 1 Watt, to use as a clutch load. R66 can
be removed from a scrap Course Computer PCB and used for this purpose.
•
A 3mm Allen Key to remove the Course Computer cover
3.2. Initial Inspection Checks
Before applying power to the Course Computer carry out following visual
inspections
:
Remove the top cover of the Course Computer, ensuring that the EMC gaskets on the
underside do not fall onto the PCB.
Visually inspect the PCB for any obvious signs of component damage or blackening,
paying particular attention to the FETs and main power components.
Using a DVM set to Ohms, check that there are no short circuits between the metal tabs of
the power devices and the heatsink.
Check that the three fuses, FS1 (30A/40A), FS2 (5A), FS3 (4A) are of the correct rating,
and are not blown.
Ensure that FS3 is set to the 12V setting.
