JVC AV-2771S Service Manual page 36

AV-2771S |
eSTATIC CONVERGENCE & DYNAMIC CONVER-
GENCE
1.
10.
11.
Connect a crosshatch generator to the input terminals and ad-
just BRIGHTNESS and CONTRAST control for a distinct pat-
tern.
Adjust the convergence around the edges of the picture tube
by tilting the yoke, up-down and left-right, and temporarily in-
stall one wedge at the top of the yoke. ( Fig. B-7, 8, 9 )
Rotate the front pair of tabs ( four pole convergence magnet )
as a unit to minimize the separation of the red and blue lines
around the center of the screen. To adjust the convergence of
red and blue, vary the. angle between the tabs ( Fig. B-5 )
Rotate the rear pair of tabs ( six pole convergence magnets )
as a unit to minimize the separation of the magenta ( R/B )
and green lines. ( Fig. B-6 )
Adjust the spacing of the rear tabs to converge the magenta
and green lines.
Apply paint to fix six magnets.
( As to models equipped with a magnet locking ring, tighten it.)
Remove the wedge installed temporarily on the yoke.
Tilting the angle of the yoke up, down and sideways, and ad-
just the yoke so as to obtain the circumference convergence.
(Fig. B-8, 9 )
Insert wedges to the position as shown in Fig. B-10 to obtain
the best circumference convergence.
Wedge has a backing of double sided adhesive tape. There-
for, tear off one side of adhesive tape, and fix the wedges.
White balance adjustment ( Black & White tracking ) can now
be performed.
eWHITE BALANCE ADJUSTMENT
( Black and White Tracking )
1,
2.
Display a monochrome pattern.
Set the RED and GREEN DRIVE VRs for their mechanical
center.
Turn the RED, GREEN and BLUE CUT-OFF VRs and the
SCREEN VR fully counterclockwise.
Display a horizontal line. ( Select the CUT-OFF SERVICE
SWITCH from N to S and a HORIZONTAL LINE will appear.)
Turn SCREEN VR _ slowly clockwise until a very faint
horizontal line appears.
Turn the CUT-OFF VR of the color which has appeared first,
clockwise by about 10°and then adjust the SCREEN VR
again so that the color may shine faintly.
Turn the other color CUT-OFF VRs slowly clockwise until a
reasonable white line appears.
Return the monochrome pattern. ( When returning a
monochrome pattern select the CUT-OFF SERVICE SWITCH
from S$ to N and a monochrome pattern will appear. )-
Adjust the RED and GREEN DRIVE VRs for best white
highlights.
36 (No.50577)
(EXAMPLE)
ANODE CGAP
(FRONT VIEW)
Fig. B-5 Fig. B-6
(REAR VIEW)
DEF. YOKE
Fig. B-7
(FRONT VIEW)
rep GREEN piue
'N
(FRONT VIEW)
GREEN
Zz XN 7
Tilting the yoke to the right will move the lines
as shown with the arrows.
(REAR VIEW)
ANODE GAP
Fix the wedges at the original position.
Fig. B-10
(FRONT VIEW)