Lcd System Adjustment; Vco Adjustment (Pd-217 Board) - Sony DSR-PD170 Service Manual

DSR-PD170/PD170P/PD190P
1-5.

LCD SYSTEM ADJUSTMENT

Note 1: The back light (fluorescent tube) is driven by a high voltage AC
power supply. Therefore, do not touch the back light holder to
avoid electrical shock.
Note 2: When replacing the LCD unit, be careful to prevent damages
caused by static electricity.
[Adjusting connector]
Most of the measuring points for adjusting the LCD system are
concentrated in CN2105 of the PD-217 board. The following table
shows the Pin No. and signal name of CN2105.
Pin No. Signal Name
1 VG
2 COM
3 GND
4 PSIG
5 HSY
Table 6-1-9.
CN2105
5 1
PD-217 board
Fig. 6-1-21.

1. VCO Adjustment (PD-217 board)

Set the VCO free-run frequency. If deviated, the LCD screen will
be blurred.
Mode
Signal
Measurement Point
Measuring Instrument
Adjustment Page
Adjustment Address
Specified Value
Note1: NTSC : DSR-PD170
PAL : DSR-PD170P/PD190P
Adjusting method:
Order Page Address Data
1 0 01
2 D A2
3 D A2
4 D A2
5
6
7
8 D A3
9 0 01
Note2: Refer to "Table 6-4-1. Hexadecimal-decimal Conversion Table".
6-34
VTR stop
No signal
Pin 5 of CN2105 (HSY)
Frequency counter
D
A2, A3
f = 15734 ± 30Hz (NTSC)
f = 15625 ± 30Hz (PAL)
Procedure
01 Set the data.
Change the data and set the
VCO frequency (f) to the
specified value.
Press PAUSE button.
Read the data, and this data is
named D .
A2
Convert D to decimal notation,
A2
and obtain D '. (Note2)
A2
Calculate D ' using following
A3
equations (Decimal calculation)
NTSC model:
When D ' 234
A2
D ' = D ' + 21
A3 A2
When D ' > 234
A2
D ' = 255
A3
PAL model:
When D ' 21
A2
D ' = D ' – 21
A3 A2
When D ' < 21
A2
D ' = 00
A3
Convert D ' to a hexadecimal
A3
number, and obtain D . (Note2)
A3
D Set the data, and press PAUSE
A3
button.
00 Set the data.