
B-70315EN/02 5.TROUBLESHOOTING
- 133 -
Type of
alarm
Condition
Upper
limit
Causes
RFI
This alarm is issued if a high RF
current flows through the discharge
tube when the oscillator is operating in
CW/pulse mode.
5.45A
Abnormal
feedback circuit
If the power supply unit fails just because the high-speed diode
or FET module is damaged, the power supply unit can be
repaired by component or PCB replacement. Other adjustments
are not required.
If the power supply unit is replaced, and adjustment is needed,
adjust the power supply unit after aging.
5.3.2 Power Supply Cannot Be Switched Off Using CRT/MDI Switch
The power supply to the unit cannot always be switched on and off. It
can be switched off only before the oscillator start switch (RUN) is
turned on or after the completion of purging with the RUN switch off
and the purge lamp lit.
5.3.3 Power Supply Cannot Be Switched On Using CRT/MDI Switch
Non-fuse breaker for IF PCB is tripping.
5.3.4 Laser Output Just after Switch On Is Low
(1) The cooling water temperature is not normal, although the chiller
unit is operating. This phenomenon may be caused when the
ambient temperature is low. In such a case, the specified
temperature will be set in five to ten minutes after the unit starts.
So, perform activation again.
(2) Slight leakage exists in the tube between laser oscillator and gas
cylinder. If the laser output in the first run after a long halt is low
and becomes normal after the second run, slight leakage may be
present in the tube between the laser oscillator and gas cylinder.
(See Subsection 3.3.2.)
Check for leakage in the gas piping system, for looseness in
joints, and for any crack in the tube. If any problem exists,
eliminate the leakage, additionally tighten the joint, or replace
the tube.