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DIDS -4 02 -2M 1 0
Para 4-1. 4!:'/4-1. 5£.
e.
Check the CRT protect at terminal Z.
If
the voltage is more than 1 V
and the sweep output is present at terminal V, check the
ve
rtical
deflection amplifier.
f.
If
deflection amplifier A2 is replaced, the replacement board must be
aligned (parag raph
Z-
3. 1).
Figure 4-4.
Horizontal Deflection Amplifier A2 Waveforms
4-1.5 Monoscope XY Deflection Amplifier A3 (figure 4-5)
a.
Check the dc voltages on the board (figure 4-1).
b.
Press only the following character keys at the beginning of the frame:
(rj}
fJ (
&
10
$.
c.
Check the four analog outputs of the monoscope:
Y outputs are at
terminals A and B;
X
outputs, at terminals J and K.
Note whether
anyone of these four output waveforms is different from that shown
in figure 4-2.
Check the minor vertical deflection signal on terminal
AB.
If it
is absent, check the output from display timing board A14,
pin 43 (figure 4-1);
it
if is present but there is no minor vertical
deflection (only horizontal lines on the CRT), proceed to
step~.
Check for presence of the blanking signal on terminal AF.
If it
is
not present, check the blanking output from display timing board A14
pin 2 (figure 4-1).
Make sure the leads to this circuit board are
properly fastened to their respective terminals.
If
proper signals
are present, check the monos cope filament, monos cope preamplifie r
A7, and video amplifier AB.
If
proper signals are absent, proceed to
the following step.
4-9
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