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CAUTION:
Before servicing this chassis, it is important that the service technician read the "Safety
Precautions" and "Product Safety Notices" in this service manual.
ATTENTION:
Avant d'effectuer l'entretien du châassis, le technicien doit lire les «Précautions de sécurité»
et les «Notices de sécurité du produit» présentés dans le présent manuel.
VORSICHT:
Vor Öffnen des Gehäuses hat der Service-Ingenieur die ,,Sicherheitshinweise" und ,,Hinweise
zur Produktsicherheit" in diesem Wartungshandbuch zu lesen.
SERVICE MANUAL
MANUEL D'ENTRETIEN
WARTUNGSHANDBUCH
Data
contained
within
this
Service
manual is subject to alteration for
improvement.
Les données fournies dans le présent
manuel d'entretien peuvent faire l'objet
de modifications en vue de perfectionner
le produit.
Die
in
diesem
Wartungshandbuch
enthaltenen Spezifikationen können sich
zwecks Verbesserungen ändern.
SPECIFICATIONS AND PARTS ARE SUBJECT TO CHANGE FOR IMPROVEMENT
Colour Monitor
June 2001
No. 0419
CM621FET


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1. DISPLAY ALIGNMENT...............................................................1
A. Times & Display Size................................................................................................... 1
B. Picture Position.............................................................................................................1
C. Linearity........................................................................................................................ 1
D. Alignment Procedure.................................................................................................... 2
E. Geometry Distortion ..................................................................................................... 2
F. Tilt................................................................................................................................. 2
G. White Balance Alignment ............................................................................................ 3
H. Preset Timing................................................................................................................4
2. CONTROL AND CONNECT LAYOUT ........................................5
A. Main PCB .....................................................................................................................5
B. Video PCB....................................................................................................................6
C. Pin Assignment............................................................................................................. 7
3.INTRODUCTION..........................................................................8
A. Power Supply................................................................................................................ 8
B. Deflection ..................................................................................................................... 8
C. Video ............................................................................................................................ 8
D. Digital Controllor ......................................................................................................... 8
4. POWER SUPPLY .......................................................................11
A. Rectifier and Filter Circuit ........................................................................................... 11
B. Flyback and PWM Circuit ............................................................................................ 11
C. Subber Circuit............................................................................................................... 11
D. Synchronized Circuit .................................................................................................... 11
E. Power Saving Circuit .................................................................................................... 11
F. Degauss Circuit ............................................................................................................. 12
G. Overload Protection Circuit ............................................................................ 12
5.DEFLECTION ..............................................................................13
A. Sync Processor.............................................................................................................. 13
B. Horizontal Processor..................................................................................................... 13
C. Vertical Output ............................................................................................................. 13
D. Dynamic Focus Section................................................................................................ 13
E. Horizontal Output Stage ............................................................................................... 13
F. Flyblack Transformer.................................................................................................... 13


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6.VIDEO AMP. CIRCUIT.................................................................16
A. Video PRE. AMP. ........................................................................................................ 16
B. Video Amplifier............................................................................................................ 16
7. TROUBLESHOOTING ................................................................19
A. Power Supply Check .................................................................................................... 19
B. Monitor Check Flow Chart........................................................................................... 20
APPENDIX A: SCHEMATIC DIAGRAMS ......................................23
APPENDIX B: DISPLAY UNIT ASSEMBLY DIAGRAMS .............27
APPENDIX C: PART LISTS ..........................................................29


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WARNING
1) This product contains components which are critical for X-radiation safety. Read the Service manual
carefully for proper replacement. Maximum 2nd anode voltage use high impedance meter, connect (-) to
chassis, use a high voltage lead from (+) to 2nd anode.
2) Critical Components are marked with the symbol of
in the material list. For continued protection
against X-radiation, replace only with same type and rating components.
3) Critical Components are marked with the symbol of # in the material list. For continued protection
against Low Radiation, replace only with same part number.
4)
This symbol warns the personnel that un-insulated voltage within the unit may have sufficient
magnitude to cause electric shock.
Therefore, it should be read carefully in order to avoid any problems.


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1
1. DISPLAY ALIGNMENT
A. TIMING & DISPLAY SIZE
For all presetting mode shall be within the limitation:
H. WIDTH
300 ± 5mm
V. HEIGHT
225 ± 3 mm
The external control range of the data area, shall be as follows;
Max. horizontal size
: overscan the screen
Min. horizontal size
:
285mm
Max. vertical size
: over the screen
Min. vertical size
:
202 mm
B. PICTURE POSITION
For all presetting mode shall be within the limitation:
H.PHASE
SCREEN CENTER ± 3 mm
V.CENTER
SCREEN CENTER ± 2 mm
The external control ranges of display for all modes listed in section 2.4
H.POSITION
50 mm
V.CENTER
25 mm
C. LINEARITY
The CONTRAST and BRIGHTNESS control shall be properly adjusted at 20 F-L with Full-intensity reverse
pattern, then change to crosshatch Pattern 12x10 (H x V), the size of grid of crosshatch pattern in every display
mode shall not vary than 5%(P) or 6%(S).If two line is next to each other, 6%(P) or 7%(S) if they are not next to
each other. The calculation formula was listed below:
H max - H min
V max - V min
x100%
or
x100%
H max + H min
V max + V min