(No. 52152) 1-43
4.10 ADJUSTMENT PROCEDURES
SCREEN VOLTAGE COARSE ADJUSTMENT
Measuring Instruments Signal generator (All-black signal, Crosshatch signal)
Oscilloscope
Card (Slot) Component/RGB Input Card (Slot 1)
Test Points Anode of CRT
TP-47B, TP-47R, TP-47G [CRT SOCKET PWB]
TP-GND [CRT SOCKET PWB]
Adjustment Points SCREEN VR [Bottom potentiometer on high-voltage transformer]
VR502 (High-voltage VR) [S.CORRECTION PWB]
FOCUS VR1 [Top potentiometer on high-voltage transformer]
FOCUS VR2 [Middle potentiometer on high-voltage transformer]
CC41 (AKB Setting) [Service Menu]
Note: Ensure that the value of CC41 (CPU BLOCK) in the Service Menu is “000”.
(1) Turn the SCREEN VR fully counterclockwise.
(2) Connect the oscilloscope across TP-47B and TP-GND.
(3) Connect the GND of high-voltage voltmeter to the braided wire.
(4) Connect the high-voltage voltmeter to the anode of the CRT and turn the
unit ON.
(5) Apply the 1080/60i component all-black signal to INPUT A.
(6)
Check that the high-voltage value is 24 to 25 kV. If it is higher than 25 kV,
adjustment the VR502 so that the high-voltage value becomes to specified value.
(7) Turn the SCREEN VR slowly clockwise until the raster lights up slightly.
(8)
Set the value of CC41 (CPU BLOCK) in the Service Menu from “000” to “002”.
(9) Turn the SCREEN VR slowly clockwise until the voltage amplitude <A> of
the AKB pulse at TP-47G is about 25 V ± 2 V.
(10)Observe the waveforms of TP-47R and TP-47B, adjust the SCREEN VR so
that the amplitude voltage <A> of the AKB pulse become to 25V ± 2V.
(11) Apply the 1080/60i crosshatch signal to INPUT A.
(12)Adjust the FOCUS VR1 and VR2 so that the entire image is in focus.
1 Vertical interval
(V. sync)
AKB pulse
V.B LK
<A>
25V ± 2V
4.10.1 SCREEN VOLTAGE COARSE ADJUSTMENT
HIGH-VOLTAGE COARSE ADJUSTMENT
Measuring Instruments Signal generator (Crosshatch signal with circle pattern)
High-voltage voltmeter
Card (Slot) Component/RGB Input Card (Slot 1)
Test Points Anode of CRT
Adjustment Points VR502 (High-Voltage VR) [S. CORRECTION PWB]
FOCUS VR1 [Top potentiometer on high-voltage transformer]
FOCUS VR2 [Middle potentiometer on high-voltage transformer]
Note: Perform the following adjustments after completing the Screen Voltage Coarse adjustment.
(1) Turn VR502 fully clockwise (the minimum position).
(2) Turn VR501 fully counterclockwise (the minimum position).
(3) Connect the high-voltage voltmeter to the anode of the CRT and turn the unit ON.
(4) Apply the 1080/60i crosshatch signal with circle pattern to INPUT A (Terminal Y on the Component/RGB Input Card).
(5)
Turn VR502 slowly counterclockwise until the value of the high voltage is about 25 kV.
(6) Adjust the FOCUS VR1 and VR2 so that the entire image is in focus.
4.10.2 HIGH-VOLTAGE COARSE ADJUSTMENT
S. CORRECTION PWB
MAIN PWB
Front side
TP-XR
TP-G
Front side
(Min) (Max)
(Min)(Max)
VR505 [CONV_V]
VR504 [CONV_H]
VR502 [H.VOLTAGE]
VR501 [X-RAY]
CN0RD
CN00R
(Top surface view of the S. CORRECTION PWB)
VR505
VR504
VR502
VR501
CN0RD
CN00R
VR502
VR501
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