
B–70115EN/03
6. TROUBLESHOOTING
153
Gas pressure anomaly in discharge tube (Refer to DGN = 905 [860])
The gas pressure is monitored after the discharge start ready condition
(LRDY) is established. This alarm is issued, if the monitored gas
pressure deviates by "100 (="1330 Pa) from the set gas pressure.
No. Cause of trouble Solution
1 Anomaly of parameter
setting of gas pressure
control
Check whether the values of PRM Nos.
15000/bit 1 [200/bit 1], 15244 [0264], 15245
[0207], and 15246 [0246] are set as indi-
cated in the attached data sheets. If a dif-
ferent value is set, set the value specified in
the data sheets.
2 Gas leakage from piping 1) Check whether any joints in the gas cir-
culating system are loose. If a loose
joint is found, tighten the joint firmly.
2) Check whether any components of the
gas circulating system are cracked. If a
cracked component is found, replace
that component.
3) Check whether there is a hole in a dis-
charge tube. If a hole is found in a dis-
charge tube, replace the discharge tube.
3 Abnormal supply laser
gas pressure setting
Adjust the secondary pressure at the regu-
lator on the gas cylinder so that the pres-
sure of laser gas supplied to the laser oscil-
lator is 0.1 to 0.2 MPa (rating) as measured
at the entry of the oscillator. If the distance
between the gas cylinder and the oscillator
is larger than 5 m, it is necessary to set the
pressure slightly higher.
4 Anomaly of pressure sen-
sor
Replace the pressure sensor.
5 The gas flow control valve
is closed.
Adjust the gas flow control valve to supply
gas at the specified flow rate.
6 Anomaly of pressure con-
trol unit
If the above checks do not reveal any ab-
normality, replace the pressure control unit.
The emergency stop button was pressed.
If the emergency stop button is pressed after the discharge start ready
condition (LRDY) is set up, the shutter is closed, discharge stops, and
the LRDY condition is resumed, then this alarm is displayed. To reset
the alarm, remove the cause of trouble, release the emergency stop
button, and press the reset key on the operator’s panel.
Alarm No. 4078 [678]
Alarm No. 4079 [679]