IBM 6551-T3N, Руководство по обслуживанию

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6551-T3N/6551-U3N
SECTION 4
ADJUSTMENTS
4-1
•
Landing Rough Adjustment
1. Enter the full white signal. (or the full black dots signal).
2. Adjust the contrast to the maximum.
3. Make the screen monogreen.
Note: Off the outputs from R ch and B ch of SG.
4. Reverse the DY, and adjust coarsely the purity magnet so
that a green raster positions in the center of screen.
5. Moving the DY forward, adjust so that an entire screen be-
comes monogreen.
6. Adjust the tilt of DY. For the TILT component, use TLV of
DY.
Note: Observe the following adjustment conditions:
“TILT” = 0
“VPIN SAW TOP” = 0
“VPIN SAW BTM” = 0
7. Lock the DY lightly with a locking fitting.
•
Landing Fine Adjustment
<Landing adjustment conditions>
a) Brightness: 1/3
∑
IK (
∑
IK = 750
µ
A)
b) Aging time: 2 hours or more.
c) Atmospheric temperature: 25
°
C
d) magnetic Field:
BH = 0
±
2
µ
T
BV = 45
±
2
µ
T (U/C, AEP)
–55
±
2
µ
T (South Hemisphere)
–10
±
2
µ
T (Equator destination)
e) Adjustment point:
1-inch inside from the edge of CRT effective tube surface.
1. Put the set inside the Helmholtz coil.
2. Set the TLH plate to “0” position.
3. Set the purity magnet of Neck Assy in “0” position, and lock
with a white pen.
4. Set “VPIN SAW TOP” and “VPIN SAW BTM” to “0” posi-
tion.
5. Receive an image of the monogreen signal.
6. Degauss the CRT and iron shield parts.
Note: Iron bottom chassis and EMI shield should be degaussed
before assembling the chassis.
7. Perform auto degaussing.
8. Attach the wobbling coil to the designated part of the CRT
neck.
9. Attach the sensor of the landing adjustment unit on the CRT
surface.
10. Adjust the DY position and purity, and the DY tilt.
Note: Use purity magnet on the DY.
11. Fasten DY with screw.
Note: Torque 22
±
2 kg•cm (2.2
±
0.2 Nm).
12. Perform auto degaussing.
13. Using two wedges, adjust vertical pins so as to attain a=b as
shown below. Further, insert two wedges as shown in the
right figure, and lock the center so that DY does not fluctuate
horizontally.
Note: Insert wedges completely so that the DY does not move.
14. If the corner landing is out of the specification, use the land-
ing magnet so as to satisfy the specification.
<Specification>
a) Green
x
±
4 x
±
7.5 x
±
4
x
±
4 x
±
7.5 x
±
4
x
±
4 x
±
7.5 x
±
4
[X] is bias value for a difference caused depending on
whether the EMI shield and rear cover are present or not.
J Models : x = 1.5 [
µ
m]
b) Difference between Green and Red, and between Green
and Blue.
±
5
±
5
±
5
±
5
±
5
±
5
±
5
±
5
±
5 [
µ
m]
c) Difference Red and Blue.
±
8
±
8
±
8
±
8
±
7
±
8
±
8
±
8
±
8 [
µ
m]
Note:
(1) Do not paste more than two magnets on one corner.
(2) Magnets will be placed in a range of 80 ~ 120 mm from the
DY along the diagonal lines.
15. After placing magnets, absolutely degauss and check the re-
sults.
16. Remove the sensor and wobbling coil.
17. Check that the DY is not tilting, and fix the purity Mg with a
white pen.
<RTV and wedge position>
(1) Apply RTV to the shaded portions.
(2) Lock CRT, wedges, and DY with RTV.
[Rear view]