JRC JMA-5104 User Manual

96
5.6 Actions to Deal with Abnormalities and Breakdown
In the case of semiconductor circuits, except in cases of problems in the design or inspection of
such circuits or causes that are external or caused by humans, breakdown or deterioration of the
circuit does not often occur. In general, the causes of breakdown that are relatively frequently
found are wire cut in the high resistance device due to high humidity, defect in the variable
resistance and defect in the contact of switches and relays.
Moreover, in many cases the cause for breakdown is not a defect in parts but rather poor
adjustment (particularly inadequate tuning adjustment) or poor maintenance (particularly defect
in cable contact) and inspecting or readjusting these aspects is often effective in the case of
perceived abnormality or breakdown. The following table should be taken into consideration in
the case of abnormalities or breakdown.
There is always a cause for a blown fuse and after replacing the fuse, it is necessary to investigate
the related circuits even when no abnormality remains. However, consideration should be given to
the fact that there is significant variance in the characteristics of fuses.
No. Condition of the Breakdown Conceivable Cause
1
Nothing appears on the
LCD.
a. Breakdown in the power supply terminal (CBD-1638);
Fuse F1 has blown
b. Breakdown in the NWZ-146 display
c. Breakdown of the main control circuit (CMC-1190)
d. The electric power of the ship is inadequate.
2
The scanner unit does not
rotate.
a. Fuse F2 and F3 have blownb.
b. Breakdown in the motor unit
(JMA-5104: CML-674 H-7BDRD0023 inside the scanner unit,
JMA-5106/5110: CBP-153/167)
3
The scanner unit rotates
but no radar image appears
(characters and markers
are, however, displayed).
a. Breakdown of the receiver
(JMA-5104: CAE-475, JMA-5106/5110: CAE-475-1)
b. Breakdown of the main control circuit (CMC-1190).
What is the condition of the transmission trigger (TI)?
c. Breakdown in the motor unit
(JMA-5104: CML-674 H-7BDRD0023 inside the scanner unit,
JMA-5106/5110: CBP-153/167)
d. Breakdown of the modulator circuit in the scanner unit
(JMA-5104: CME-322, JMA-5106: CME-323,
JMA-5110: CPA-24)
4
The operation switches do
not work.
a.
If the switches do not work even after turning the power
on again, breakdown is in the main control circuit
(CMC-1190).
b. Breakdown is in the panel circuit (CCK-892)
c. Cut in the cable connecting the operation unit.
(H-7ZCNA0855)

JRC JMA-5104 Specifications

General

Brand	JRC
Model	JMA-5104
Category	Marine Radar
Language	English