GDM-FW9011
SECTION 3
SAFETY RELATED ADJUSTMENT
When replacing or repairing the shown below table, thec) Beam Current Protector Circuit Check
following operational checks must be performed as a(1st Protector): D Board
safety precaution against X-rays emissions from the unit.
1) Apply 4.5 V DC to CN504 0 pin on the D board,
Part Replaced ([)and check high voltage value.
2) Connect constant current source to a section between
HV ADJRV901T902 (FBT) qa pin and qs pin (GND) on the D board,
and check that high voltage checked in 1) lowers byPart Replaced (])
1.50 kV or more when the specified current flows to
HV RegulatorD Board IC901, R923, R924,the qa pin.
Circuit Check[Specification]: 2.00 + 0.00/� 0.01 mAR929, R943, T902(FBT)
Y Mounted D Board
HV ProtectorD Board C922, C926, D912,
Circuit Checkd) Beam Current Protector Circuit CheckD915, D921, Q907,
Q908, R921, R922,
R932, R937, R939,(2nd Protector): D Board
1) Connect constant current source to a section betweenT902(FBT)
T902 (FBT) qa pin and qs pin (GND) on the D board,Y Mounted D Board
Beam CurrentD Board C921, C933, D901,and check that the voltage of CN504 0 pin becomes
Protector CircuitD913, R920, R928,
Check0 V or less when the specified current flows to the qaR930, R931, T902(FBT)
pin.Y Mounted D Board
[Specification]: 1.63 + 0.00/� 0.01 mAN Board IC001, R031, R032
Y Mounted N Board
* Confirm one minute after turning on the power.
a) HV Regulator Circuit Checke) Beam Current Protector Circuit Check
1) Enter black crosshatch signal (black on white back-: G Board
ground), and check that high voltage is in the speci-1) Apply 264 V AC.
fied range.2) Enter about 5 V to CN650 4 pin on the G board, and
[Specification]: 28.50 ? 0.10 kVcheck that the output voltage of CN653 2 pin is
2) Check that the voltage of D912 cathode on the Dabout 15 V.
board is 29.0 V or more.3) Enter about 0 ? 0.2 V to CN650 4 pin, and check
that the output voltage of CN653 2 pin becomes 1.0
b) HV Protector Circuit CheckV or less.
1) Enter black crosshatch signal (black on white back-
ground).f) Beam Current Protector Circuit Check
2) Apply the specified voltage to the D912 cathode on: N Board
the D board, and check that high voltage is 0.1 kV or
1) Check that the protector operates, when the voltage
less.of CN010 qh pin on the N board is lowered to 0 V or
[Specification]: 34.00 + 0.00/� 0.05 Vless (for more than 2 seconds).
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