Panasonic WE-MV180A Service Manual page 12

8
Adjust VR301 so that the rising edge of the Burst Gate
Pulse from the end of the Burst signal becomes 200 ± 100
ns as shown in Fig. 4-13.
TP312
(CSIG)
TP301
(BGPP)
Fig. 4-13
(13) VCXO Adjustment
Test Point: TP302 (APC)
TP313 (DACSIG)
Adjust: VC301 (VCXO)
8
Connect CH1 of the Oscilloscope to TP313 and CH2 to
TP302.
8
Trigger the Oscilloscope at TP309.
8
Adjust VC301 so that the Burst signal becomes stable at
TP313 and center position of lock limitation, the DC
voltage at TP302 should be 2.8 – 3.0 V DC as shown in
Fig. 4-14.
Note: Use Ceramic Screwdriver.
TP302
(APC)
TP313
(DACSIG)
Fig. 4-14
(14) Chroma D/A Level Adjustment
Test Point: TP313 (DACSIG)
TP314 (XCDASIG)
Adjust: VR307 (CDAGA)
8
Disconnect the Connector of the Camera Unit from CN1
on the Video Board.
8
Supply 100% Colour Bar signal from S-Video signal
output of the Video Signal Generator to the Test Points
TP1 (YIN) and TP7 (CIN) on the Video Board using an
Extension Cable.
8
Set the Positive mode by the Nega Button.
8
Connect CH1 of the Oscilloscope to TP314 and CH2 to
TP313.
200 ± 100 ns
Video Board
Video Board
Video Board
limitation
of lock
Adjust center
of limitation
2.8 - 3.0 V DC
at TP313.
GND Level
Video Board
Video Board
Video Board
8
Trigger the Oscilloscope at TP309.
8
Adjust VR307 so that the both Burst signals at TP313 and
TP314 become same amplitudes (± 5%) as shown in Fig.
4-15.
TP314
(XCDASIG)
TP313
(DACSIG)
(15) Chroma A/D Offset Adjustment
Test Point: TP313 (DACSIG)
Adjust: VR303 (CADOF)
8
Connect the Oscilloscope to TP313.
8
Trigger the Oscilloscope at TP309.
8
Select the Negative mode by the Nega Button.
8
Adjust VR303 so that the Burst signal becomes symmetry
as shown in Fig. 4-16.
TP313
(DACSIG)
(16) Chroma A/D Level Adjustment
Test Point: TP311 (CMSIG)
TP312 (CSIG)
TP313 (DACSIG)
Adjust: VR304 (CADGA)
8
Connect CH1 of the Oscilloscope to TP312 and CH2 to
TP311.
8
Trigger the Oscilloscope at TP309.
8
Set the Positive mode by the Nega Button.
8
Adjust VR8 so that the both Burst signals at TP311 and
TP312 become same amplitudes (± 5%) as shown in Fig.
4-17.
9
Adjust same
amplitude as
TP313
Adjust same
amplitude as
TP314
Fig. 4-15
Video Board
Video Board
V1
V2
Adjust V1 = V2.
Fig. 4-16
Video Board
Video Board
Video Board
Video Board