Operation Manual

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8-17
８
8.2 TROUBLESHOOTING
In case of semiconductor circuits, it is deemed that there is 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 any clear cause. When a fuse is replaced, it is necessary to check the
related circuits even if there is no trouble. In this case, note that there is some dispersion in the
fusing characteristics. Table 8.7 shows a list of fuses used in the equipment.
Table 8.7 Fuse List
Location Parts No.
Nominal
Current
Protection Circuit Type
Transmitter-
receiver Unit
F1 1A Rectifier circuit PC1001 MF51NN-1A
Display Unit
(NSK)
F1 to F4 0.5A LOG.NSK circuit PC4201 MF60NR-0.5A