JVC HV-53PRO/K Service Manual page 25

■ ■ ■ ■ FOCUS & BEAM SPOT ADJUSTMENT
Measuring
Item
instrument
Adjustment of Signal
FOCUS & Generator
BEAM SPOT
Similar
adhesive
(Securing
adhesive)
CRT FOCUS adjustment
Test point Adjustment part
G Def. Yoke (DY)
R Def. Yoke (DY)
B Def. Yoke (DY)
R/G/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 CRT
neck]
R FOCUS VR
G FOCUS VR
B FOCUS VR
[FOCUS PACK]
No. 51984
Description
1. Receive a cross-hatch signal.
2. Press the ZOOM key and select the REGULAR mode.
3. If the picture tilted, adjust the R, G and B DY.
LENS FOCUS
4. Makes a red single colour.
NOTE : When making a single colour, It squeezes SCREEN VR in
each one, or it does a lid to the lens in of the adjustment
colour and it makes it single colour.
5. 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.
6. In the same manner, produce green and blue single colours
and adjust their respective focus.
7. 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
8. Receive a dot signal.
9. Makes a red single colour.
NOTE : When making a single colour, It squeezes SCREEN VR in
each one, or it does a lid to the lens in of the adjustment
colour and it makes it single colour.
10. Turn the R FOCUS VR to set the dot diameter to about 30mm.
11. Turn the 4 pole magnet of the projection unit CRT neck and to
where the dots at the screen center are nearly circular.
12. Return the R FOCUS VR to its original position.
13. Turn the 2 pole magnet of the CRT neck to minimize expansion
of the dots.
14. Receive a crosshatch signal.
15. Adjust the overall screen focus.
16. In the same manner, adjust for the green and blue single
colour. focus.
17. Secure the 4 and 2 pole magnets with similar adhesive.
CRT FOCUS
18. Receive a crosshatch signal.
19. Makes a red single colour.
NOTE : When making a single colour, It squeezes SCREEN VR in
each one, or it does a lid to the lens in of the adjustment
colour and it makes it single colour.
20. Adjust the R FOCUS VR for optimum focus at the position
indicated in the figure.
21. In the same manner, adjust for the green and blue single
colour. focus.
22. After adjustment, return the SCREEN VRs to their original
positions.
NOTE : When moving screen VR, always return to original.
HV-53PRO
25