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DEFLECTION
TROUBLESHOOTING
(Deflection and High Voltage Drive Signals)
I oov
IHOl
.
. /
vp-p =
3.906
v
Pin 12
From pin 4 it reenters
Freq =
33.78
kHz
DC Voltage
= 3.59Vdc
IHOl at Pin 10 and is
t
-
output again at pin 12.
13
%
4
I
1
.
I
This signal is then
routed to IH02 pin 10.
IH02 is the High Voft-
age Drive IC and regula-
tor.
14
IHO
Pin 10
l . 00"
/
vp-p = 3.95 Y
Frcq = 33.70 kHz
DC Voltage =1.803 Vdc
r----i--
l
I.&w
lO.W/
, By utilizing feedback
voltage from the Focus
block assembly which
has been leveled shifted
by QH04 and QHO5, the
internal comparator
makes a comparison
between the feedback
Figure 17 illustrates the comparison of the waveform
supplied to Pin 1 of THOl when compared to PDDl
Connector Pin 7 H. DRIVE signal.
Figure 17 illustrates the comparison of the waveform
input to Pin 1 of IHOl when compared to PDDl Con-
nector Pin 7 H. DRIVE signal. This signal is also pro-
vided as an input to Pin 10.
2 .oov
2 2mv
J70.0os
1o.oy/
1
IH01
Pin 1
I
I
I I
I
17
voltage and the crossover point of the internally gener-
ated Sawtooth and outputs the signal shown in figure
15 from pin 7.
The output from IH02 pin 7 is sent through the pre-
drivers QHO8 through
QHlO and is finally
delivered to the base
of QHOl , the High
DC Voltage = 3.22Vd.s
Voltage Horizontal
output Transistor.
The Deflection Hori-
'
zontal Pulse produced by Q777 is utilized by the High
Voltage section as it's drive signal. This signal must
be present for the High Voltage section to function.
This signal is routed to IHOl to be processed into the
actual drive signal for the High Voltage section.
IHOl outputs this signa from Pin 10
b 2*oov 2 zoov
IH01
Pin 10
HORIZONTAL
WAVEFORMES
COMPARED
TO H DRIVE
The Deflection H. Drive signal deveIoped by 4755,
I
PDDl
Connedar
Pin 7
: I
H. DRIVE
I I
A = 2.6
US
I *
(See Figure 7) is routed to IHOl pin 1, (See Figure 11). T
,
,
I
I
,
1
I
The output of Pin 4 of IHOl is compared to Horizontal
Drive signal in Figure 18.
.
2 2cmV
ro.oos
1o.oy/
I I
IHCIl
Pin 4
I I
18
I I
!
Iy---
I
I
1
I
I
I
PDDl
Connector
Pin 7
H. DRIVE
: i
d
= 2.6
US
I
4
,
I
I
\
% 1
l
:
I
The following waveforms give a visual example of the
Signal Process as it eventually arrives at the base of
,
.
,
i
I I
the Horizontal Output Transistor QHOl, (See Figure
16).
PAGE 02-l 1
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