T.O. 33A1-3-358-11/TM 11-6625-842-15
Section IV
Paragraphs 4-30 to 4-37
NAVAIR 16-30APM239-2
.
REMEDY
PROBABLE CAUSE
TROUBLE
Improper reference volt-
Check R3, VR1, CR5,
Defective reference regulator.
ages appear at MODE C
CR6, C2 on TB1. Re-
place defective components.
ENCODER jack.
,
Improper current read-
Replace ammeter.
Defective ammeter.
ing.
l
Figure 4-3. Troubleshooting Chart (Sheet 2 of 2)
4-30. DISASSEMBLY AND ASSEMBLY.
4-31. TRANSPONDER SET CONTROL
Remove the transponder set control from the test set by loosening the four captive turnlock
a.
fasteners at the corners of the set control front panel.
Gently pull the set control from the test set front panel far enough, to gain access to plug P1 which
b.
is connected to the rear of the set control.
Remove plug P1 from the connector on the rear of the set control.
c.
4-32. TEST SET FRONT PANEL.
a.
Loosen 13 captive front-panel attachment screws (index no. 142, figure 5-3).
Gently pull the test set from its case. All components are then accessible.
b.
4-33. FAULT ISOLATION METER. Remove four screws (index no. 23, figure 5-5) and separate the front
panel assembly from the case. All components are then accessible.
4-34. COMPONENT REMOVAL.
Tag the leads to components that are to be removed in order to facilitate reassembly.
a.
CAUTION
When unsoldering or soldering semiconductor devices, provide an
adequate heat sink between the component and the end of the lead
being heated to prevent damage to the component.
b.
Carefully unsolder the leads of the component to be removed.
4-35. REASSEMBLY. Reassembly of all components and assemblies is accomplished by reversing the pro-
cedures contained in paragraphs 4-31 through 4-34.
4-36. SCHEMATIC DIAGRAMS.
4-37. The schematic diagrams are illustrated in figures 4-4 and 4-5. Figure 4-4 is the schematic of the test
set itself, figure 4-5 is the schematic of the fault isolation meter. Wiring information is contained in figure
4-6.
4-7
