JRC JMR-611 - Fault Finding

7.1 FAULT FINDING


7-3
7
7.1 FAULT FINDING
In case of semiconductor circuits, it is deemed that there are few cases in which the used semiconductor devices
have inferior quality or performance deterioration except due to insufficient design or inspection or by other
external and artificial causes. In general, the relatively many causes are disconnection in a high-value resistor
due to moisture, a defective variable resistor and poor contact of a switch or relay.
Some troubles are caused by defective parts, imperfect adjustment (such as tuning adjustment) or insufficient
service (such as poor cable contact). It will also be effective to check and readjust these points.
Melted fuses are caused by clear cause. When a fuse is replaced, it is necessary to check the related circuits
even if there is no trouble. In checking, note that there is some dispersion in the fusing characteristics.
Table 7-1, 2 shows a list of alarm message displayed on the screen.
Table 7-1 Alarm message list (SYSTEM FAILURE)
ALARM TYPE
MASSAGE
Description
SYSTEM FAILURE
TXRX(SSW Off)
Scanner: Safety switch OFF.
TXRX(AZI)
Scanner: Azimuth error.
TXRX(MHV)
Scanner: Modulator’s high voltage alarm.
TXRX(Trigger)
Scanner: TRIGGER error.
TXRX(HL)
Scanner: HL (antenna directional standard signal) error.
TXRX(Data)
Scanner: No communication, communication mismatched,
checksum error, or collision
TXRX(Heater)
Scanner: Magnetron heater voltage error.
TXRX(Reverse)
Scanner: Reverse rotation.
TXRX(Video)
Scanner: VIDEO error.
Keyboard(Data)
Operation unit: Communication error or checksum error.
GPS(Status)
GPS status error.
GPS(LAT/LON)
Latitude/ Longitude (GPS): No communication or data error.
GPS(Date/Time)
Date/ Time (GPS): No communication or data error.
GPS(Speed)
Speed(GPS): No communication or data error.
PROC(Interrupt)
Process unit: Interrupt error.
PROC(AZI)
Process unit: Azimuth error.
PROC(HL)
Process unit: HL (antenna directional standard signal) error.
PROC(Video)
Process unit: VIDEO error.
PROC(Trigger)
Process unit: TRIGGER error.
AIS(Data)
AIS: No communication or data error.
AIS Alarm ***
Process unit: AIS equipment error.
Heading(Data)
Heading: No communication or data error.
Depth 1
Water depth: No communication or data error.
Depth 2
Water depth: No communication or data error.
Turn(Data)
Rate of turn: No communication or data error.
Rudder(Data)
Rudder: No communication or data error.
Pilot(Data)
Auto-pilot: No communication or data error.
TRIP(Data)
TRIP: No communication or data error.
Out of Bounds
Own ship’s latitude is over 85°N or 85°S.
I/F Controller(Data)
Process unit: No communication or data error with I/F circuit