Actions To Deal With Abnormalities And Breakdown - JRC JMA-5104 Instruction Manual

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
Nothing appears on the
1
LCD.
The scanner unit does not
2
rotate.
The scanner unit rotates
but no radar image appears
3
(characters
are, however, displayed).
The operation switches do
4
not work.
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.
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)
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
and markers
(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)
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)
Conceivable Cause
96