Sony DVP-S7700, Руководство по обслуживанию, Страница: 103 / 129

7-4
8. Checking RGB Output B
(MB-84 board) (AEP, UK model)
<Purpose>
This checks RGB output B. If it is incorrect, pictures will not be
displayed correctly in spite of connection to the TV with an EURO
AV connecting cord.
Mode
Video Encoder (IC252) check in test
mode menu “0” Syscon Diagnosis
Signal Color bars
Test point
EURO AV 1 (RGB)-TV connector
7
pin (75
Ω
terminated)
Instrument Oscilloscope
Specification 700 ± 30 mVp-p
Checking method:
1) Confirm that the B-Y level is 700 ± 30 mVp-p.
Figure 7-9
9. Checking S Video Output S-C (MB-84 board)
<Purpose>
This checks whether the S-C satisfies the NTSC Standard. If it is
not correct, the colors will be too dark or light.
Mode
Video Encoder (IC252) check in test
mode menu “0” Syscon Diagnosis
Signal Color bars
Test point CN252
!™
pin
Instrument Oscilloscope
Specification 286 ± 20 mVp-p
Connection:
Checking method:
1) Confirm that the S-C burst is 286 ± 20 mVp-p.
Figure 7-10
700 ± 30 mVp-p
286 ± 20 mVp-p
10. Checking S Video Output DC Level (MB-84 board)
<Purpose>
This checks signals for S1 and S2 compatible TV. If they are not
correct, the TV will not switch automatically to letter box, etc.
Mode
Video Encoder (IC252) check in test
mode menu “0” Syscon Diagnosis
Signal Color bars
Test point CN252
!™
pin
Instrument Digital voltmeter
Specification
S-terminal 0 V: 0 Vdc
S-terminal 5 V: 5.0 Vdc
Connection:
Checking method:
1) In the test mode initial menu “0” Syscon Diagnosis, select S-
terminal 0 V.
Confirm that the voltage at CN252
!™
pin is 0 Vdc.
2) Press any key to select S-terminal 5 V.
Confirm that the voltage at CN252
!™
pin is 5.0 Vdc.
11
12
100
µ
F
75
Ω
±
1%
100k
±
1%
CN252
+
Oscilloscope
+0
–1.5
11
12
100
µ
F
75
Ω
±
1%
100k
±
1%
CN252
+
Digital voltmeter
+0
–1.5