Adjustments - Dell P780 - 17" CRT Display Service Manual

Connect the communication cable of the connector located on the D board on the monitor. Run the service software and then follow the
instructions.
IBM AT Computer
as a Jig
D-sub
(9 Pin [female])
*
Allow a 30 minute warm-up period prior to making the following adjustments:
4-1. Landing Rough Adjustment
1. Display the all white pattern.
2. Adjust the contrast to maximum value.
3. Display the plain green pattern.
4. Slide the DY back and roughly adjust the plain green
pattern with the purity magnet so that it is centered on
the screen.
5. Moving the DY forward, adjust so that an entire screen
becomes pure green.
6. Adjust the tilt of DY and tighten lightly with a clamp.
4-2. Landing Fine Adjustment
1. Place the monitor in the Helmholtz coil.
2. Set TLH plate to zero position.
3. Display plain green pattern.
4. Degauss CRT face and iron parts with degauss equipment or
hand-degausser.
5. Perform auto degauss.
6. Attach a wobbling coil to the specified position of CRT neck.
7. Put the sensor of landing checker to CRT face.
8. Adjust purity, DY position and DY tilt.
9. Tighten DY screw.
10. Perform auto degauss.
11. Adjust top and bottom pin by pitching DY up and down with
two wedges so that [a] is equal to [b].
SECTION 4

ADJUSTMENTS

1 1-690-391-21 2 A-1500-819-A
Interface Unit
mini Din
4 Pin
(8Pin)
*
The parts above ( ~ ) are necessary for DAS adjustment.
1 3
— 13 —
3 3-702-691-01
Connector Attachment
To BUS CONNECTOR
4 Pin 4 Pin
12. If the corner landing is out of specification, use a disk
magnet for the landing correction.
13. If disk magnets were used, perform an auto degauss.
14. Remove the wobbling coil and sensor.
15. Fix the purity magnet on DY with white paint.
4-3. Convergence Rough Adjustment
1. Enter the white crosshatch signal.
2. Roughly adjust the horizontal (H.STAT) and vertical
(V.STAT) convergence at four-pole magnet.
3. Roughly adjust HMC and VMC at six-pole magnet.
4-4. Convergence and V. Key (H. Trp) Fine Adjustment
Purity
Magnet
Neck Ass'y
A Board
4-pole
6-pole
Mg
1. Display crosshatch pattern with green lines and black field.
2. Adjust V. Key (=H. Trapezoid) with H-Trp VR so that [a]
is equal to [b].
3. Change "CONV_OFF_NDX" to "7".
H-Trp VR TLV VR
XCV VR
DY CRT
YCV VR
Mg
TLH Plate
P780