Siemens 21T3, Service Manual

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21T3 (E) 3-1
SECTION 3
ADJUSTMENTS
Note: Hand degauss must be used on stand-by or power-off condition.
This model has an automatic earth magnetism correction function by using an earth magnetism sensor and a LCC coil. When
using a hand degauss while monitor (LCC coil) is being operated, it sometimes gets magnetized, and the system may not
work properly as a result.
•
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".