Sony KDP-57XBR2 Training Manual page 59

Video Appears In Both Boxes: The main and sub video process paths are working correctly. The MID is sending
the video directly into IC511. The problem is likely located on the BR board. The DRC
constantly running and not controlled by the I²C bus. IC511 controls the selection of the video source. If video
signals are present at pins 67, 69 and 69 of IC511, replace IC511. No signals at these pins indicate the BR board
is not sending up-converted video. Check to see if video is entering the BR board and the 3.3V and 5V lines are
OK. If they are present, replace the BR board. It is not serviceable.
Video Appears In Left Box Only: The sub video path is OK. Once again, the DRC
small number of components to check. Begin working your way back from the YUV switch, IC1307. Scope the
video signal path back through the main decoder, 3D comb filter, A/D converter and A/V switch IC until you find
a signal and troubleshoot the isolated component.
Screen Is Still Blank: Assuming high voltage is present and the set in not in AKB blanking, this leaves IC511 as
the cause. It is not able to process video from either of the inputs from the MID
need to check the RGB output path to the CRT boards. Since the unit is not showing AKB problems, the IK
pulses are getting to the CRTs via this path.
Gray Background Appears With Two Black Boxes: IC511 is OK. This signal is generated by the MID. The main
and sub video paths are not working. Since a failure in both paths at the same time is unlikely, suspect A/V
switch, IC515.
As you can see, the MID
techniques were accomplished by using the very basic video block diagram in Figure 12-1. Block diagrams
providing more detail will be provided in the pages that follow to assist in troubleshooting the isolated section.
J505
3 4
D550
V
L
R
DET
OUT 2
TU501
Q506
MAIN
TUNER
L OUT
BTF - WA
411
R OUT
DET
OUT 2
Q526
TU501
SUB
TUNER
BTF - WA
L OUT
411
R OUT
TM
circuit provides an excellent troubleshooting tool for video problems. All of the above
C697
R821
R875
D524
C698
R823
R876 +9V
D525
R843
R862
R907 R824
C706
R819
R891
D532
R820
C707
D537
R892
C708
R822
R870
D543
+9V
C689
R510
N R554
R808
P
Q517
R560
R804
C685
R814
C690
+9V
C686 R794
R607
N
R664
P
Q518
R682
C688
R790
FROM
R799
C687
IC1008
MAIN CPU
FIGURE 12-2 - INPUT SWITCHING
56
Y1
3 Y
MAIN
C
58
52
L
C1
5
54
R
V OUT 53
6
SSW1
R759
49
Y IN
1
V1
R755
SUB V OUT
42
2
L1
R736
SUB C IN
40
4
R1
IC515
AVU SWITCH
CXA1845Q
38
SUB Y IN
TV V
63
SUB Y OUT
45
MAIN
47
SUB C OUT
34
35
TV
36
62
L MAIN
25
64
TV R MAIN
29
TV V SUB
60 7
12
13
18
59 TV L SUB
19
TV R SUB
61
24
32 SDA
31 SCL
56
12. RA-4 Video Circuit Troubleshooting
TM
circuit on this board is
TM
is bypassed. This leaves a
TM TM
or DRC
TO BUFFER Q532
TO BUFFER Q536
TO CN512/1
TO CN512/3
Q533
N
R720
R816
C673
C664
+9V
N
Q548
R727
C643
L523
C639
R745
TO IC1302/28
TO IC1301/32
SELECT OUT
J502
FRONT VIDEO 2 J3201
VIDEO 3 J506
VIDEO 4 J507
VIDEO 5 J508
ALL ZENERS ARE UDZ - 10B
circuits. There is no
TO K
BOARD
+9V
CM501
4
VIDEO
IN
Y OUT
1
C656
R717
A BOARD
12.2TVP14 6/5/02