Electrical Adjustment; Standard Video Level; Vcom Dc Level - Sony DVP-FX921 Service Manual

This section describes procedures and instructions necessary for
adjusting electrical circuits in this set.
Instruments required:
1) Color monitor TV
2) Oscilloscope 1 or 2 phenomena, band width over 100 MHz,
with delay mode
3) Frequency counter (over 8 digits)
4) Digital voltmeter
5) Standard commander (RMT-D191)
6) DVD reference disc
HLX-504 (J-6090-088-A) (single layer) (NTSC)
HLX-505 (J-6090-089-A) (dual layer) (NTSC)
DVP-FX921/FX921K/FX930/FX930CC/FX930WM/FX935
SECTION 7

ELECTRICAL ADJUSTMENT

7-1.
1. Checking Video Output Level
<Purpose>
This checks whether video output level satisfy the NTSC standard.
If it is not correct, the brightness will be too large or small.
Signal
Measurement Point
Measuring Instrument
Specification
Checking method:
1) Confirm that the video output level is 1.00 ± 0.02 Vp-p.
7-2.
1. VCOM DC Level Adjustment
<Purpose>
When the LCD Board or LCD is replaced, the VCOM DC Level
Adjustment is necessary.
Signal
Measurement Point
Measuring Instrument
Specification
Adjusting method:
1) Adjust the VR1 to attain 3.8 V to 3.9 V.
LCD BOARD (SIDE A)
7-1E

STANDARD VIDEO LEVEL

Mode
Check the color-bar (100%) signal on DVD
reference disc
LINE OUT (VIDEO) connector
(75 Ω terminated)
Oscilloscope
1.00 ± 0.02 Vp-p
Fig 7-1

VCOM DC LEVEL

Mode
Arbitrary
VCOM (LCD Board)
Digital voltmeter
3.8 V to 3.9 V
VCOM
VR1
Fig 7-2
Play
1.00 ± 0.02 Vp-p
Play