Sony KDP-57XBR2 Training Manual page 100

E-W
IC309
6
PIN 47
A BOARD H DRIVE
14
Q8020
Q8016
Q8004
H DRIVE
IC309
PIN 40
A BOARD
Q8030
Q8023
T8002
HDT
Vertical Deflection Troubleshooting
No Vertical Deflection: The first instinct of the technician is to go after the vertical output IC8003 and understandably
so. It is a drive component with heavy current usage and heat dissipation, and it is usually the cause of the
failure..
The first check that you should perform (and this applies to all Sony televisions of the last seven years) is to
check the voltage level of the clock and data lines on the I
(sometimes SCL and SDA). The DC voltage should not be lower than 4.6 volts. If either of these lines is loaded
down, the vertical oscillator will not start. This is the number one cause of multiple component replacements for
a simple vertical problem. You should always check the clock and data level whenever you have a strange
problem and, particularly, if it appears that you more than one problem. Although most television chassis will not
produce vertical deflection, some will generate other symptoms. As an example: The AA-2W used in Sony's
KV32/36XBR200 sets will display a magenta colored raster with no video and insufficient vertical height. Assuming
the bus is okay, move onto the next step.
Since this chassis will go into protect mode and shut the unit down, certain measurements must be taken and
watched for during the time the unit powers up and shuts down. Unlike previous designs, the V stop feature
cannot be overridden since pin 35 of IC309 is looking for vertical pulses from Q8001. Always remove the C
boards from the tubes when servicing a no vertical sweep condition.
The ± 15V lines are the first to check. If OK, place a scope probe and watch for a moment of vertical sawtooth
signal at pin 1 or 7 of IC8003. Any presence of drive signal here indicates IC309 is generating V drive and
isolates the problem to the output circuits. Verify vertical ramp signal on the high side of R8036 or R8039 in the
return circuit. The circuit could be running and Q8001 is not sending the V signal to IC3006.
135V
12V
2
IC8005
Q8027
CTL
3
1
112VDC
4
Q8024
H OUT
FIGURE 24-1 - HORIZONTAL DEFLECTION RA-6 CHASSIS
200V TO
DF CIRCUITS
D8033
2
1
T8003
HOT
D8045
D8032
H CENT.
Q8031
TO A BOARD
Q8101
2 C bus. They are conveniently labeled SCLK and SDAT
97
24. RA-6 Deflection Circuit Troubleshooting
IC8009
5
-
+
3
C8137
+
IC8012
+
3
1
-
2
Q8039
H PULSE
H OUT
1
DYB
H RET
4
H OUT
1
DYR
H RET
4
H OUT
1
DYG
H RET
4
IC8019
HLC
24.1TVP14 7/17/02