Sony MV-900SDS Service Manual page 15

5. NTSC SUB CARRIER CHECK
Setting:
MONITOR board
TP510
TP513
Procedure:
1. Connect a frequency counter (high impedance) to the TP510
and TP513 on the MONITOR board.
2. Check that the voltage between TP951 (–) and TP952 (+) is
14.4 V. Press the [POWER] button to turn the power on.
3. In the normal mode, press the [INPUT] key on the remote
commander to select the "VIDEO" mode.
4. Input NTSC video signal to the "VIDEO INPUT" jack (J701
on the VIDEO (IN) board).
5. Check that the value of frequency counter is 3.579545 MHz
±100 Hz.
6. PAL SUB CARRIER CHECK
Setting:
MONITOR board
TP510
TP513
Procedure:
1. Connect a frequency counter (high impedance) to the TP510
and TP513 on the MONITOR board.
2. Check that the voltage between TP951 (–) and TP952 (+) is
14.4 V. Press the [POWER] button to turn the power on.
3. In the normal mode, press the [INPUT] key on the remote
commander to select the "VIDEO" mode.
4. Input PAL video signal to the "VIDEO INPUT" jack (J701 on
the VIDEO (IN) board).
5. Check that the value of frequency counter is 4.433619 MHz
±100 Hz.
7. V-COM ADJUSTMENT
Setting:
MONITOR board
TP819
TP832
Procedure:
– Voltage Set-up Adjustment –
1. Connect an oscilloscope to the TP819 and TP832 on the
MONITOR board.
2. Check that the voltage between TP951 (–) and TP952 (+) is
14.4 V. Press the [POWER] button to turn the power on.
3. Enter the test mode, and enter the "2. FOR FACTORY" mode.
(refer to "4. TEST MODE")
4. Press the [MENU] button to display "Com Gain", and press
the [REVERSE] button.
5. Adjust by pressing the [+]/
oscilloscope becomes 6.3 Vp-p ±0.1 V.
6. Press the [REVERSE] button and write the date to EEPROM
(IC402 on the MONITOR board).
frequency counter
+
–
frequency counter
+
–
oscilloscope
+
–
buttons so that the voltage of
–
6.3 Vp-p ± 0.1 V
– Waveform Position Set-up Adjustment –
7. Adjust the RV802 on the MONITOR board so that A value
of waveform becomes –1.7 V ±0.1 V.
0 V
8. VIDEO ADJUSTMENT
Note: Perform the following adjustment items in test mode.
Common Setting:
1. Check that the voltage between TP951 (–) and TP952 (+) is
14.4 V. Press the [POWER] button to turn the power on.
2. Enter the test mode, and enter the "2. FOR FACTORY" mode.
(refer to "4. TEST MODE")
3. Set the signal format system to NTSC. (refer to "4. TEST
MODE")
4. Input 10 steps signal (NTSC, without burst) to the VIDEO
INPUT jack (J301 on the POWER board) from pattern
generator.
Waveform of input signal
0.286 V
fig. 8-1
Waveform of output signal
(TP810, TP811, TP812)
0 V
A B C D E
fig. 8-2
1 Contrast Level of Luminance Signal
Setting:
MONITOR board
TP811
TP513
Procedure:
1. Connect an oscilloscope to the TP513 and TP811 on the
MONITOR board.
2. Press the [MENU] button to display "Y Gain", and press the
[REVERSE] button.
3. Adjust by pressing the [+]/
waveform (fig. 8-2) becomes 3.4 V
4. Press the [REVERSE] button and write the date to EEPROM
(IC402 on the MONITOR board).
MV-900SDS
4.6 V ± 0.1 V
A : – 1.7 V ± 0.1 V
1 Vp-p
oscilloscope
+
–
buttons so that the D value of
–
+0.2
V.
–0.1
15