44
10. RA-4/4A Deflection Circuit Troubleshooting
D BOARD
8
9
C5020
R5063
Q5019
R5072
R5069
R5068
N
FROM
C5041
AC VOLTAGE
DIVIDER IN
H OUT
R5027
N
-12V
FROM IC6001
R5024
Q5016
R5048
R5061
Q5014
P
R5039
R5042
C5026
D5014
Q5015
N
R5020
R5058
Q5009
P
D5008
R5033
C5020
H.P.
R5030
R5018
C5011
D5006
R5023
R5013
D5002
R5004
CN506
H
PROTECT
TO IC1009/PIN 3
A BOARD
C5002
N
Q5006
H BLK
(HP)
TO
A BOARD
CN509
CN5004
FIGURE 10-4 - H PROTECT / HP
10.4TVP14
7/17/02
Vertical Deflection
Figure 10-5 illustrates the vertical processing circuitry primarily created by VDSP IC512. Synchronization is
achieved by VS entering pin 22. Notice the ½ H signal entering at pin 16. Since this unit generates internal,
interlaced, horizontal scan, the vertical must be phase locked to start the odd and even scan in the proper
location. The parabolic pincushion correction waveform exits pin 11 and vertical drive is output at pin 1 as a
sawtooth.
Figure 10-6 shows the usual output design. An operational amplifier is used with negative feedback from the
deflection yoke return to maintain linear amplification of the drive signal. It is simple and works quite well. You
rarely see vertical linearity problems with this design. As with the pincushion circuit, the vertical circuit seems to
cause problems for many technicians.