6558-03N/03S/43N/43S
SECTION 3
SAFETY RELATED ADJUSTMENT
When replacing or repairing the shown below table, thea) HV Regulator Circuit Check
following operational checks must be performed as a1) Confirm that the voltage of the pin 2 of CN901 on
safety precaution against X-rays emissions from the unit.D board is within the voltage range shown below.
Standard: 9.00 ? 0.065 VDCPart Replaced (])
b) HV Protector Circuit CheckHV Regulator D Board IC901, T902
Circuit Check? Mounted D board
1) Confirm that the HV protector circuit works and TVHV Protector D Board Q660, Q661, D916,
Raster disappears when apply the voltage as shown
below between pin 3 of CN901 on D board andCircuit CheckD935, C924, R665,
GND using an external DC power supply.R667, R940, R980,
T902
? Mounted D boardCheck Condition: Less than 34.10 VDC
G Board PH680, Q680, Q683,
c) Beam Current Protector Circuit Check-1D680, R680, R685,
1) Measure HV voltage and record that value.R686, R687, R688,
R689
? Mounted G board2) Shorted between pin 1 and pin 4 of CN901 on D
board.Beam Current D Board IC901, D904, D907,
3) Connect to the Constant Current Jig (A) between pinProtector CircuitD908, R011, R908,
CheckR909, R921, R925,1 of CN901 on D board and GND, confirm that the
R926, R929, R930,Beam Current Protector Circuit works and HV go
T902down more than 1.25 kV from the value of (1).
Check Condition: 1.50 mA? Mounted D board
Check Condition
d) Beam Current Protector Circuit Check-2
1) Connect to the Constant Current Jig (B) between pinInput voltage : 100 ~ 240 VAC
1 of CN901 on D board and GND, confirm that theInput signal : White Cross Hatch at 107 kHz
Beam Current Protector Circuit works and TV Ras-Beam control : BRT and CONT ? Minimum
B+ voltage : 195 ~ 205 VDC
ter disappears.
Check Condition: 1.59 mA
e) Voltage of 3rd winding of FBT
1) Confirm that the voltage of pin 3 of CN901 on D
board is within the voltage range shown below.
Standard: more than 28.0 VDC
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