CPD-G520
SECTION 3
SAFETY RELATED ADJUSTMENT
3-1
HV Regulator
Circuit Check
HV Protector
Circuit Check
Beam Current
Protector Circuit
Check
When replacing or repairing the shown below table, the
following operational checks must be performed as a
safety precaution against X-rays emissions from the unit.
Part Replaced (
[
)
RV901
HV ADJ
*
Confirm one minute after turning on the power.
a) HV Regulator Circuit Check
1) Turn the RV901 slowly, and adjustment so that high
voltage is in the specified range.
[Specification]: 27.00 ± 0.05 kV
2) Check that the voltage of D912 cathode on the D
board is 17.0 V or more.
b) HV Protector Circuit Check
1) Using external DC Power Supply, apply the voltage
shown below between cathode of D912 and GND,
and check that the RASTER disappers.
[Specification]: 19.95 + 0.00/– 0.05 V
c) Beam Current Protector Circuit Check
1) Connect constant current source to a section between
T901 (FBT)
qa
pin and GND, and check that the
RASTER disappers when the specified current flows
to the
qa
pin.
[Specification]: 2.12 + 0.00/– 0.01 mA
Part Replaced (
]
)
D Board C925, IC901, R901,
R902, R905, R924,
R925, R926, RV901,
T901 (FBT)
• Mounted D Board
D Board C920, C923, D911,
D912, R903, R917,
R918, R919, R920,
R923, T901 (FBT)
• Mounted D Board
N Board IC1001, RB1001
• Mounted N Board
D Board C930, D917, R921,
R932, R933, R935,
T901 (FBT)
• Mounted D Board
N Board IC1001, RB1001
• Mounted N Board