Adjustments - HP D2846 Service Manual

• 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. Adjust the tilt of DY, and fix lightly with a clamp.
Note: "TILT" shall be set at 0.
• Landing Fine Adjustment
1. Put the set inside the Helmholtz coil. ("LCC SW" = "12")
2. Input the single green signal and set the CONT control to
MAX.
Note: After the W/B adjustment with 9300K, measure an average
of SIk when a full white signal is entered in the CONT
MAX/BRT CENT status. Then make adjustment so that the
specified screen can be attained after aging for 2 hours with
Ik equivalent to 30% of the average value.
3. Demagnetize the metal part of the chassis with the hand de-
gausser and coil degausser, and the CRT surface with the
hand degausser.
Input AC 230V to AC IN, turn on and off the power to per-
form auto degaussing. (Perform auto degaussing by setting
"MON CON REG2"=152. Return to the original value after
use.)
Demagnetize the CRT surface with the hand degausser again.
Note:
(1) Hand degauss must be used on stand-by or power-off condi-
tion.
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.
(2) Adjust in a non-magnetic field. BV=45uT.
(3) If adjusting in a magnetic fields, add the shift from the non-
magnetic field in your estimation.
4. Attach the wobbling coil to the designated part of the CRT
neck.
5. Attach the sensor of the landing adjustment unit on the CRT
surface.
6. Adjust the DY position and purity, and the DY tilt, and land-
ing of the center and 4 corners with the landing checker.
After adjustment, set "LCC SW" to "13".
• Write terrestrial magnetism sensor reading VX and VY to
"LCC VX" and LCC VY" respectively. Adjust the landing
by moving "LCC NS", "LCC LT", "LCC LB", "LCC RT"
and "LCC RB". However, the register adjustment must be
limited within the following range.
"LCC NS"
"LCC LT", "LCC LB", "LCC RT", "LCC RB"
Save the service data.
SECTION 4

ADJUSTMENTS

<Specifications>
Adjust so that the green is within
the specification given right.
4 corner adjust target : within ± 1
The red and blue must be within
the specification given right with
respect to the green.
A difference between red and blue
must be within the specification
given right.
* Adjustment and measurement should be made at the points one
inch inside the fluorescent screen.
7. For the up/down swing, swing the DY and insert a wedge so
that the up and down pins are equal at the top and bottom.
Adjust the DY TLV VR so that the horizontal trapezoid is
equal at the left and right. Insert the wedge firmly so that the
DY does not shake.
8. Check the landing of each corner, and if it does not satisfy the
specification, adjust the landing of four corners using "LCC
LT", "LCC LB", "LCC RT" and "LCC RB".
However, the register adjustment must be limited within the
following range.
"LCC NS"
"LCC LT", "LCC LB", "LCC RT", "LCC RB" 128 ± 40
After adjustment, save the service data.
9. Remove the sensor and wobbling coil.
10. Switch the signal to R.G.B., and check that each color is pure.
11. Check that the DY is not tilting.
128 ± 15
128 ± 40
– 19 –
D2846
(µm)
0 ± 3 0 ± 7.5 0 ± 3
0 ± 5 0 ± 5 0 ± 5
0 ± 3 0 ± 7.5 0 ± 3
(µm)
± 6 ± 6 ± 6
± 6 ± 4 ± 6
± 6 ± 6 ± 6
(µm)
10 10 10
10 7 10
10 10 10
128 ± 15