Sony DXF-20W, Service Manual

Page: 14 / 36

2-4 (E)
DXF-20W
2-2-5. Bright Calibration Adjustment
Note
This adjustment and “2-2-2. Focus Adjustment”, “2-2-3.
Horizontal Frame Adjustment” and “2-2-4. Heater Voltage
Adjustment” affect with each other. Therefore, repeat the
adjustment until all specifications are met.
Preparation
.
Viewfinder
BRIGHT control
→
Mechanical center
CONTRAST control
→
Mechanical center
Adjustment Procedure
Change the setting of aspect ratio to 4:3 mode.
Adjust the bright calibration so that the pedestal level
becomes the surrounding black level by turning
1
RV204
(SUS-BRIGHT: 4:3) / the VA-229 board clockwise from
the counterclockwise maximum point.
Set the aspect ratio to 16:9 mode again.
Adjust
1 RV206 (SUS-BRIGHT: 16:9) / the VA-229 board
in the same way as the 4:3 mode.
2-2-4. Heater Voltage Adjustment
Note
When performing this adjustment, check “2-2-5. Bright
Calibration Adjustment”.
Preparation
. Measuring equipment: Digital voltmeter (AC mode)
Adjustment procedure
Check the following voltage.
.
Test point: TP3
↔
TP4/VF-88 board
.
Specification: 0.635
±
0.015 V rms
If the above specification is not met, adjust 1 RV4 (VH-
ADJ)/VF-88 board so that the specification is met.
VF-88 board
VF-88 board
TP4
RV4
TP3
RV3
RV2
RV1
RV204
RV206
VA-229 board