Chapter 5 Troubleshooting
22
5.1 Error Messages
The following messages appear to call the operator’s attention to missing heading or bearing
pulses. Check the antenna cable for damage or discontinuity when these messages appear.
Table 5-1 Error Messages
Message Meaning
NO HEADING PULSE Heading pulse is not applied to the CPU on the DU board. The heading
mark disappears.
NO BEARING PULSE Bearing pulse is not applied to the CPU on the DU board. Radar
automatically changes from TX to ST-BY mode.
5.2 Troubleshooting Matrix table
The troubleshooting matrix table on the next page helps the service technician to quickly identify
defective pcb or block. To use the table, locate the symptom in one of the three columns of the
table. Possibly defective circuits and their likelihood of defectiveness, identified by a circle, star
or triangle, corresponding to 70 to 80 %, approximately 20 % and a few percent respectively, are
listed in each column. Numeral inside circle shows degree of possibility; the smaller the number,
the higher the possibility.
Note: Before consulting the table, check the ship’s mains (input voltage at J1351#1(+) and #2(-)
of the display unit: 10.8 to 31.2 VDC) and the power fuse.
To Next Page
Loading...
