Sony ICF-DVD57TV Service Manual page 19

5-3. PLL ADJUSTMENT
Connection:
set
Adjusting Procedure:
1. Connect a digital voltmeter to the TP1651 and TP1901 (GND)
on the MONITOR board.
2. Adjust the RV1651 so that the reading of digital voltmeter is
2.2 ± 0.15 V.
5-4. V COM ADJUSTMENT
Connection:
set
Adjusting Procedure:
Connect an oscilloscope to the TP1960 and TP1901 (GND) on the
MONITOR board.
5-4-1. Voltage Set Up Adjustment
Adjust the set so that the A level of the waveform on the oscilloscope
is 6.6 ± 0.1 Vp-p. (Refer to the 5-7. video bus adjustment)
5-4-2. Position Set Up Adjustment
Check the B level of the waveform on the oscilloscope is 4.7 ± 0.1
Vp-p and adjust the RV1501 so that the C level of the waveform
on the oscilloscope is –1.9 ± 0.1 Vp-p.
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digital
voltmeter
TP1651
+
–
TP1901 (GND)
TP1960
osclloscope
+
–
TP1901 (GND)
A
B
0V
C
5-5. OSD DOT CLOCK CHECK
Connection:
TP1515
set
Adjusting Procedure:
1. Connect an frequency counter to the TP1515 and TP1901
(GND) on the MONITOR board.
2. Check that the reading of frequency counter is 6.5 ± 0.2 MHz.
5-6. NTSC SUB CARRIER CHECK
Connection:
TP1510
set
Checking Procedure:
1. Connect an frequency counter to the TP1510 and TP1901
(GND) on the MONITOR board.
2. Check that the reading of frequency counter is 3.579545 MHz
± 100 Hz.
5-7. VIDEO BUS ADJUSTMENT
Connection: (5-7-1 to 5-7-9)
INPUT VIDEO jack
(JK501)
NTSC pattern
generator
set
Condition: (5-7-1 to 5-7-9)
Input the NTSC video signal (10 step (no burst)) (1 Vp-p 75 Ω) to
the INPUT VIDEO jack (JK501) on the MAIN board from NTSC
pattern generator.
Adjusting Procedure:
1. Set the TV test mode (Refer to TV TEST MODE (See page
13).
2. Press the [TV MENU] key to select "LOAD DEFAULT", and
press the [ENTER] key to write initial values to the EEPROM.
Note: It carries out, only when EEPROM (IC1451) is exchanged.
3. Press the [TV MENU] key to select "FOR FACTORY", and press
the [ENTER] key to enter the adjustment mode.
4. If entering the adjustment mode, press the [TV MENU] key to
select item, and press the [ENTER] key to execute all adjustment
items mentioned below.
ICF-DVD57TV
frequency counter
(high impedance probe)
+
–
TP1901 (GND)
frequency counter
(high impedance probe)
+
–
TP1901 (GND)
TP1963 or
TP1964 or
TP1965
osclloscope
+
–
TP1901 (GND)
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