JVC AV-65WP74/HA Service Manual page 50

AV-65WP74
3.8.3 FOCUS & BEAM SPOT ADJUSTMENT
Measuring
Item
instrument
FOCUS & Signal
generator
BEAM SPOT
adjustment
Similar
adhesive
(Securing
adhesive)
LENS FOCUS
SCREW
PROJECTION UNIT & LENS ASS'Y
1-50 (No.52096)
All manuals and user guides at all-guides.com
Test point
R Def. Yoke (DY)
G Def. Yoke (DY)
B Def. Yoke (DY)
[PROJECTION UNIT]
R LENS FOCUS screw
G LENS FOCUS screw
B LENS FOCUS screw
[PROJECTION UNIT
(LENS ASS'Y)]
R SCREEN VR
G SCREEN VR
B SCREEN VR
[FOCUS PACK]
4 pole magnet
2 pole magnet
[PROJECTION UNIT
(R / G / B CRT neck)]
R FOCUS VR
G FOCUS VR
B FOCUS VR
[FOCUS PACK]
DEFLECTION
YOKE
CENTERING
MAGNET
4 POLE 2 POLE
MAGNET MAGNET
(CRT adjustment location)
CRT FOCUS adjustment point
Adjustment part
(1) Receive NTSC cross-hatch signal.
(2) Press [ASPECT] key and select FULL mode.
(3) If the picture tilted, adjust the R, G and B DY position
to mark straight horizontal line.
LENS FOCUS
(1) Makes a red single color.
NOTE :
When making a single color, It squeezes SCREEN
VR in each one, or it does a lid to the lens in of the
adjustment color and it makes it single color.
(2) By turning the LENS FOCUS screw (in LENS
ASS'Y), for optimum focus at the screen center.
Check for absence of difference in the peripheral
focus. If the peripheral focus is poor, slightly shift the
center focus to obtain overall balanced focus.
(3) In the same manner, produce green and blue single
color and adjust their respective focus.
(4) After adjustment, it fixes a screw.
NOTE :
There is not a difference in the focus in the top and the
bottom, on either side, in the diagonal.
When the difference of the focus is big, it removes a
main lens, and it puts a washer between the main
lens and the coupler and it adjusts it.
BEAM SPOT
(5) Receive NTSC dot pattern signal.
(6) Makes a red single color.
NOTE :
When making a single color, It squeezes SCREEN
VR in each one, or it does a lid to the lens in of the
adjustment color and it makes it single color.
(7) Turn the R FOCUS VR to set the dot diameter to
about Ø30mm.
(8) Turn the 4 pole magnet of the projection unit CRT
neck and to where the dots at the screen center are
nearly circular.
(9) Return the R FOCUS VR to its original position (just
focus).
(10) Turn the 2 pole magnet of the CRT neck to minimize
expansion of the dots.
(11) In the same manner, adjust for the green and blue
single color focus.
(12) Secure the 4 and 2 pole magnets with similar
adhesive.
CRT FOCUS
(13) Receive NTSC crosshatch signal.
(14) Makes a red single color.
NOTE :
When making a single color, It squeezes SCREEN
VR in each one, or it does a lid to the lens in of the
adjustment color and it makes it single color.
(15) Adjust the R FOCUS VR for optimum focus at the
position indicated in the figure.
(16) In the same manner, adjust for the green and blue
single color focus.
(17) After adjustment, return the SCREEN VRs to their
original positions.
NOTE :
When moving screen VR, always return to original.
Description