JVC GR-AX640U, Service Manual

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3.2 ELECTRONIC VIEWFINDER (E. VF) ADJUSTMENT
(For GR-AX640U/UC)
Notes:
•
Unless otherwise specified, all measurement points and
adjustment parts are located on E. VF board.
• After adjustment or replacement of the deflection yoke or
the centering magnet, fix it by the band as shown the figure
below.
CENTERING
MAGNET
CRT
TOP VIEW
STOPPER
Fig. 3-2-1 E. VF
• After adjustment is completed, compare the picture on the
E. VF screen with the monitor TV.
CENTERING
MAGNET
CRT
F.B.T
STOPPER
Fig. 3-2-2 E. VF
Fig. 3-2-3 E. VF board
Subject • Alignment tape
• Stairstep
Mode • PB
Equipment • E. VF
Measurement point • E. VF screen
Adjusting part • Deflection yoke
Specification • The picture is visible as
same as monitor TV.
3.2.1 Tilt
1) Put the deflection yoke to the most inner side of CRT neck
first. Then fix the stopper temporary.
2) Adjust the tilt of picture on the E. VF screen by tilting the
deflection yoke.
3) Fix the stopper completely.
3.2.2 Centering
Subject • Alignment tape
• Stairstep
Mode • PB
Equipment • E. VF
Measurement point • E. VF screen
Adjusting part • Centering magnet (CRT assy)
Specification • The center of the E. VF screen
1) While observing the viewfinder screen, adjust the centering
magnet to locate the stairstep in the center of the view-
finder screen.
Subject • Camera picture
Mode • EE
Equipment • E. VF
Measurement point • E. VF screen
Adjusting part • VR7001 (V. SIZE)
Specification • Normal picture amplitude
3.2.3 Vertical scanning
1) Observing the viewfinder screen, adjust VR7001 for
normal picture amplitude.
3.2.4 Brightness
Subject
•
–
Mode • EE
• Lens closed
Equipment • E. VF
Measurement point • E. VF screen
Adjusting part • VR7002 (BRIGHT)
Specification • The CRT raster is just barely
visible
1) Close the lens with the cap and adjust VR7002 so that
the raster of the CRT is just visible in the E. VF.
3.2.5 Focus
Subject • Camera picture
Mode • EE
Equipment • E. VF
Measurement point • E. VF screen
Adjusting part • VR7003 (FOCUS)
Specification • The center area is clear and
defined
1) While observing the viewfinder screen, adjust VR7003
so that the picture at the central area of the screen is
clear and defined.
VR7001
V. SIZE
VR7002
BRIGHT
6 0 E. VF PWB ASSY
CN7001
T7001
CN7002
VR7003
FOCUS
3-3