TM 9-6625-1753-14
Table 5-4. Troubleshooting Delaying Sweep Plug-In Type 74-13A - Continued
Table 5-4. Troubleshooting Delaying Sweep Plug-In Type 74-13A - Continued
Malfunction
Probable cause
Corrective action
Malfunction
Probable cause
Corrective action
Erratic triggering or no triggering with
Defective automatic trigger circuit.
Check
Q8201
and
its
associated
No output from + GATE connector
Defective
delayed-sweep
gate
Check Q8106, Q8107 and their
AUTO-NORM switch at AUTO.
components; replace the defective
(delayed sweep).
associated components; replace the
transistor or component (fig. 5-12).
defective transistor or component (fig.
Does
not
trigger
when
the
Open capacitors C8205, C8203
Replace the defective capacitor.
Measure the voltages as shown on the
COUPLING switch is set to AC.
(normal sweep); capacitors C8105,
functional schematic to help isolate
C8103 (delayed sweep).
the defective component.
Does
not
trigger
when
the
Open
capacitor
C8203
(normal
Replace the defective capacitor.
No output from the SAW connector.
Defective
normal-sweep
gate
Check Q8206, Q8207 and their
COUPLING switch is set to ACF.
sweep), C8103 (delayed sweep).
associated components; replace the
Insufficient horizontal deflection.
Defective stage in the horizontal
Check Q8301, Q8302, Q8303, Q8304,
defective transistor or component (fig.
deflection amplifier.
Q8305, Q8306, Q8307, Q8308, Q8309,
and Q8311 and their associated
Defective disconnect diode.
Check CR8205, CR8209, CR8211,
components; replace the defective
CR8216; replace the defective diode.
transistor or component (figs. 5-11 and
Defective Miller integrator.
Check V8203, V8204 and their
associated components; replace the
Measure the voltages as shown on the
defective tube or component (fig. 5-
functional schematic to help isolate the
defective stage.
Defective turn-off emitter follower.
Check Q8208 and its associated
Sweep rate calibration incorrect at
Defective resistor or capacitor in the
Replace the defective resistor or capacitor.
components; replace the defective
one position of the TIME/DIV
RC timing circuit.
transistor or component (fig. 5-11).
switch.
Measure the voltages as shown on the
Sweeps are not linear.
Defective Miller integrator.
Check V8203, V8204 (normal sweep) and
functional schematic to help isolate
their associated components; replace
the defective stage.
the defective tube or component. Check
Beam position indicators don't function.
Defective beam position lamps.
Check DS8302, DS8301 and replace
V8103, V8104, (delayed sweep) and
the defective lamps.
their associated components; replace
Defective horizontal deflection amplifier.
Check Q8301, Q8302, Q8303, Q8304,
the defective tube or component (fig. 5-
Q8305, Q8306, Q8307, Q8308,
Q8309 Q8311 and their associated
Measure the voltage as shown on the
components; replace the defective
functional schematic to help isolate the
transistors or defective component
defective component.
Sweep is unstable at certain positions
Defective lockout circuit.
Check capacitors C8559 and C8558;
Measure the voltages as shown on the
of the TIME/DIV SWITCH.
replace the defective capacitors.
functional schematic to help isolate the
Sweep is unstable at all positions of
Defective lockout circuit.
Check Q8208, capacitor C8563, and
defective stage.
the TIME/DIV switch.
diodes CR8207, CR8206; replace the
defective transistor, capacitor, or diode
Sweep retrace is visible.
Defective lockout circuit.
Check Q8208, capacitor C8563, and
diodes CR8207, CR8206; replace the
defective transistor, capacitor, or diode
No output from + GATE connector
Defective
normal-sweep
gate
Check Q8206, Q8207 and their associated
(normal sweep).
components; replace the defective
component (fig. 5-11).
Measure the voltages as shown on the
functional schematic to help isolate the
defective component.
5-8
