Board Replacement Repairs - Sony KD-34XBR2 Training Manual

Chart 11-3 - Horizontal Sync Levels – Input is 15.735kHz NTSC at Video 1
Location
CN005/pin A8
CN005/pin A4
CN8801/pin A6
CN001/pin C18

Board Replacement Repairs

The following are very simplified signal flow diagrams used to quickly see the Main, Twin and HD signal paths
for board isolation. The paths are the same in the HA-3 and RA-5A TV chassis because they use the same B
and Q box that houses the bulk of the video signal processing.
Main Video Path
When a single picture is chosen from the analog tuner or video inputs, the path shown in Figure 11-6 applies.
QM BD.
U BD.
VIDEO
1,
VIDEO
3-6
HD BD.
VIDEO
2
Only the main signal path is used to direct the analog composite video from the rear panel (U board) or main tuner
(A board). Component video (Y, Pb, Pr) with H & V sync lines is sent to the QM board for conversion into a high
resolution, high frequency video signal to match that of the TV.
The OSD IC buffers the component video signal before leaving the QM board and returning to the B board. SW
IC002 on the B board acts as a pass-through for the video signal. Both component video and sync from the QM
board leave the B board and enter the Y/C CRT Drive IC on the A board. From the A board, the RGB signal is
output to the CRT cathodes.
Board Description
B Output - Main H from B board
B Output - Sub H from B board
QM Output – Pix sync from MID circuit
B Output – Final pix sync from QM bd or Video
5 or 6, 1080i input signal
Hi SCAN VIDEO/33.75kHz
MID
PROCESS
PROCESS
B BD.
MAIN
A/V
SW.
PROCESS
FIGURE 11-6 - NTSC MAIN PIX VIDEO PATH
11. Video Process - HA-3 and RA-5A Chassis
DRC
OSD
NTSC
MAIN
SW.
ANALOG
IC002
VIDEO
SW.
44
Frequency Vp-p
15.735kHz 3.5Vp-p
15.735kHz 3.6Vp-p
33.75kHz 3.7Vp-p
33.75kHz 5Vp-p
MAIN
PIX
RGB OUT
TO C BD.
A BD.
CRT
DRIVE
ANALOG
TUNER
8TVP12 1325 9/4/01