Table
4-2.
TROUBLE-SHOOTING GUIDE
(continued)
Symptom
Blown Line Fuse
Power
Supply Malfunctions
No
output Signal ....
but
SYNC
output normal
No SYNC
Output. . . .
but Output normal
No SINE
Output
TRIANGLE and
SQUARE are OK
Badly Distorted SINE
Output . .
TRIANGLE is OK
No
SYNC and
50S2 OUTput
. . .
SQUARE WAVE
Output
has Abnormally
Slow Rise
or
Fall
Times
Corrective
Action
Replace
FI
with a slow blow fuse
of the proper
amperage.
If fuse blows
again, check the following:
a) Q45 or Q47
may be shorted between the collector
and
emitter.
b)
Q1, Q8,
Q10,
or Q16 may be shorted
to the heat sink
bracket.
c)
A capacitor
or transistor
may
be
shorted.
d) Check for loose
wires or solder
bridges on each printed
circuit board.
If there is a
symptom of
power supply malfunction, disconnect
all wires
between the power supply board and
the
main
board
and check
the following:
a)
All power supply output
voltages.
If all
are
either
too
high
or too
low, the trouble is probably in the
+15 V supply
as all supplies are directly or
indirectly referenced to
it.
b) Check
CR9 through CR12. A
defective
or
incorrectly
polarized diode will cause the integrated
circuits
to
latch up.
c)
Reference voltage
at
collector of Q9 should be
+6.6 V
±0.3
V with
+15
V in normal condition.
The output
amplifier is malfunctioning;
see Output Amplifier Check outlined below.
The Sync Amplifier is
malfunctioning;
see Sync
Amplifier Check outlined below. Also check Q19
and Q20 for proper operation.
Sine Amplifier is
malfunctioning;
See Sine
Amplifier
Check outlined below.
Sine Module is malfunctioning and should be replaced. First
check Q34 or Q35 for
possible
trouble.
The Triangle Generator is not functioning properly. Check
Triangle Amplifier,
Hysteresis
Switch,
Diode Gate, and VCG
circuits.
Check all
bypass capacitors (Cl
03,
Cl
04,
C93, C94 and C97)
in the
Output Amplifier. Check
Output Amplifier
as outlined
below.
TRIANGLE
Output has Constant Check Q23 and Q25 for possible trouble;
then check
IC4
and
Positive Slope with change of Frequency IC6 and their
associated
circuitry.
TRIANGLE
Output has Constant
Check
Q22 and Q24 for possible trouble; then check ICS
and
Negative slope with
Change
of Frequency
IC5
and their
associated circuitry.
Checks
VCG
Amplifier
&
1C3-IC6
With SYMMETRY
control
set to NORM, slowly turn
FREQ
DIAL from
0.1 to 10 and
observe the following:
4-5
11/70
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