Sony CPD-G420 (serv.man3) Service Manual ▷ View online
CPD-G420(E)
2-1
SECTION 2
SAFETY RELATED ADJUSTMENT
HV Regulator
Circuit Check
Circuit Check
HV Protector
Circuit Check
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
Part Replaced (
])
D Board C925, IC901, R901,
R902, R905, R924,
R925, R926, RV901,
T901 (FBT)
• Mounted D Board
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
R918, R919, R920,
R923, T901 (FBT)
• Mounted D Board
N Board IC1001, RB1001
• Mounted N Board
Beam Current
Protector Circuit
Check
Protector Circuit
Check
Part Replaced (
])
D Board C930, D917, R921,
R932, R933, R935,
T901 (FBT)
• Mounted D Board
T901 (FBT)
• Mounted D Board
N Board IC1001, RB1001
• Mounted N Board
CPD-G420(E)
2-2
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
CPD-G420(E)
3-1
SECTION 3
ADJUSTMENTS
•
Landing Rough Adjustment
1. Display all white pattern (or black dot pattern).
2. Set contrast to 255.
3. Display green plain pattern.
4. Side back DY and roughly adjust green plain pattern to be centered on
the useful screen with Purity Magnet.
5. Adjust DY tilt.
Note: Set ROTATION to 128 and LCC_NS to 128 when adjusting DY tilt.
6. LIghtly tighten the DY screw.
•
Landing Fine Adjustment
Note: (1) After adjust W/B (9300k), measure the average of IK with all
white video input, while CONTRAST is maximum and
BRIGHTNESS is center. And adjustment shall be made so that
the miss-landing become least after aging 2H with the IK 30% of
measured value shown above.
(2) The magnetic field shall be BH = 0.
(3) When adjusting at other than BH = 0, calculate the shifted value
from BH = 0.
1. Put the monitor in helmholz coil.
2. Set as follows;
LCC_SW = 0
(LCC Correction Current = 0)
FUNCTION_SW bit1 = (Auto Degauss = On)
CONTRAST = 255
3. Display green plain pattern.
4.
Degauss the iron part of chassis with a hand degausser and degauss coil.
5.
Degauss CRT face with a hand degausser again.
6.
Input AC 230V to AC IN and turn the monitor off and on. Then auto-
degauss works.
7.
Reset FUNCTION_SW bit1 to 0 (auto-degauss = off)
8.
Degauss CRT face with a hand degausser again.
9.
Attach wobbling coil to the specified place on CRT neck.
10. Put on landing sensor to CRT face.
11. Set LCC_SW to 12.
12. With landing checker, adjust DY position, purity, DY center and
landing of the 4 corners.
13. Read VX and VY value which are the read out of magnetic sensor, and
write to "LCC_VX_REF" and "LCC_VY_REF".
14. Adjust landing by LCC_NS, LCC_LT, LCC_LB, LCC_RT, and
LCC_RB. Adjustment of registers shall be limited within the following
range.
LCC_NS: 128 ± 15
LCC_LT, LCC_LB, LCC_RT, and LCC_RB: 128 ± 40
± 6
± 6
± 6
± 6
± 6
± 6
± 6
± 6
± 6
(µm)
The red and blue must be within the
specification given right with re-
spect to the green.
specification given right with re-
spect to the green.
<Specifications>
Adjust so that the green is within
the specification given right.
4 corner adjust target : within ± 1
Adjust so that the green is within
the specification given right.
4 corner adjust target : within ± 1
0 ± 3 0 ± 7.5 0 ± 3
0 ± 3 0 ± 7.5 0 ± 3
0 ± 3 0 ± 7.5 0 ± 3
(µm)
CPD-G420(E)
3-2
Set LCC_SW to 12, and Perform Service Save.
15. Tighten DY screw within specified torque, and auto-degauss.
Note: Torque 22 ± 2 kgcm (2.2 ± 0.2Nm)
16. Adjust the vertical angle of DY to make top and bottom pins equal (a =
b). The horizontal angle shall not be changed (straight). Settle DY
upright without leaning, and insert wedges firmly so that DY shall not
move.
a
b
c
d
<How to place wedge>
Green plain crosshatch pattern
Green plain crosshatch pattern
a and b should be equal.
c and d should be equal.
c and d should be equal.
Plaster RTV to both sides for the upper wedge.
Make sure that they settle inside DY.
Plaster RTV to one side for other wedges.
17. Adjust top and bottom pins correction VR.
18. Adjust the horizontal trapezoid distortion by DY horizontal trapezoid
correction VR.
19. Adjust landing by LCC_NS, LCC_LT, LCC_LB, LCC_RT and
LCC_RB. Adjustment of registers shall be limited within the following
range.
LCC_NS: 128 ± 15
LCC_LT, LCC_LB, LCC_RT, and LCC_RB: 128 ± 40
20. Remove the sensor and wobbling coil.
21. Switch signals to R, G, and B, and then check that the pure colors have
good color purity.
22. Fix purity magnets with white paint.
10
10
10
10
7
10
10
10
10
(µm)
A difference between red and blue
must be within the specification
given right.
must be within the specification
given right.
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