B-70265EN/02 5.TROUBLESHOOTING
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5.3.5 Display of Fluctuating Laser Output on CRT
First check if PRM No. 15216 is taking the value of 60, which is a
standard. In case the fluctuation continues with this value used, read
the laser output monitor value indicated in DGN=906. Its range of
fluctuation is smaller than ±50. If it exceeds this value, check the
followings.
(1) Is the coaxial cable between the laser power sensor mounted on
the rear mirror holder and the intermediate PCB B (A16B-1600-
0361) or the cable between the intermediate PCB B and the IF
PCB (A16B-2100-0142) inside the laser oscillator fixed tightly?
(2) Is there anomaly in the laser power sensor output? Is the DC
resistor between the terminals of the power sensor unit in the
range 100Ω-500Ω?
(3) Check the input signal (LPWI-0V) of the intermediate PCB B.
If there exists any anomaly in the results of the above investigations,
replace the anomalous component.
5.3.6 Circuit Breaker for Cooling Fan, Solenoid Valve, and
Stabilized Power Supply Trips
If a load short-circuit such as a burn-in of a fan motor coil occurs in
the cooling fan, solenoid valve, or stabilized power supply, the circuit
breaker (NBK1) trips. Replace the component in which the load short-
circuit occurred, and check the cabling to the component. Replace a
cable if it is abnormal.
5.3.7 Electromagnetic Contactor of Exhaust Pump Trips Thermally
Possible causes are listed below. Take appropriate action.
No. Cause of trouble Solution
1 Anomalous setting of
thermal relay
Ascertain if the setting of the contactor is
done at correct value. If not so, correct it.
(setting value = 5.5A)
2 Too high viscosity of oil 1) Check if the room temperature is lower
than 5 degree. If so, raise it.
2) Check the deterioration of oil which
causes the viscosity increase. If so,
change it.
3 Reverse rotation direction
of pump
The normal direction is counterclockwise
when seen from the side of motor fan. If not
so, correct it at the terminal.
4 Excessive oil During pump operation, check the oil level
through the oil check window. If the oil level
is between L and H, the oil level is regarded
as normal.
5 Undesignated oil is used. Use the designated oil.
6 Exhaust filter choked. Replace it.