Focus Adjustment; G2 (Screen) And White Balance Adjustments - Sony KV-XA21M30 Service Manual

KV-XA21M30/XA21M63
RM-952
KV-XA21N90
RM-915
Fix a Permalloy assy corresponding to the misconverged
areas.
a
d
Permalloy assembly

3-3. FOCUS ADJUSTMENT

FOCUS adjustment should be completed before W/B adjustment.
1. Receive digital monoscope pattern.
2. Set "Picture Mode" to "DYNAMIC".
3. Adjust focus VR so that the center of screen becomes just
focus.
4. Change the receiving signal to white pattern and blue back.
5. Confirm magenta ring is not noticeable. Incase magenta is very
obvious, adjust focus VR to take balance of magenta ring and
focus.
Focus
Screen
FLYBACK TRANSFORMER (T503)
b
c
3-4. G2 (SCREEN) AND WHITE BALANCE
ADJUSTMENTS
1. G2 (SCREEN) ADJUSTMENT
1) Set the PICTURE to normal.
2) Put to VIDEO input mode without signals.
3) Connect R, G and B of the C1 board cathode to the
oscilloscope.
4) Adjust BRIGHTNESS to obtain the cathode voltage to the
value below.
5) Adjust G2 (screen) on the FBT until picture shows the point
before cut off.
2. WHITE BALANCE ADJUSTMENT
1) Set to Service Mode (Refer Section 5-1: ADJUSTMENTS
WITH COMMANDER).
2) Input white raster signal.
3) Set the PICTURE to minimum.
4) Select GCT (WHB 4) and BCT (WHB 5) with [1] and [4], and
adjust the level with [3] and [6] for the best white balance.
5) Set the PICTURE to maximum.
6) Select GDR (WHB 1) and BDR (WHB 2) with [1] and [4],
and adjust the level with [3] and [6] for the best white
balance.
7) Write into the memory by pressing [MUTING] then [0].
3. SUB BRIGHT ADJUSTMENT
1) Set to service mode.
2) Input a staircase signal of black to white from the pattern
generator.
3) BRIGHTNESS .... 50%.
PICTURE ............ MINIMUM
4) Select SBR (WHB7) with [1] and [4], and adjust SBR
(WHB7) level with [3] and [6] so that the second stripe from
the right is dimly lit.
White
– 36 –
Cathode setting voltage:
175 V ± 2 (VDC)
0 V
second from the right
Black