TM 5-6630-215-12
Table 4-1.
Troubleshooting, Orgainizational
MALFUNCTION
TEST/INSPECTION
CORRECTIVE ACTION
Step 2.
Upon completion of the actions in step 1, without suc-
cess,
the trouble should be considered to be electrical.
Refer to figure 4-1 for test point locations.
Some of the voltage checks must be made with ac
power applied to the instrument.
Use caution
when performing these checks to avoid touching
exposed leads and connections.
NOTE
A VOM rated at 20,000 ohms/volts DC, 5000 ohms/
volts AC or better should be used.
Test Point
Location
Voltage
Probable Defect
TP1
TP2
TP3
TP4
TP5
Line Votlage Plug
PowerCablePlug
Amplifier Circuit Board
Amplifier Circuit Board
Lamp Cable Plug
110 Vdc or 220 Vdc
8 Vdc (ac oper) 4.8 Vdc
(batt)
3 Vdc
2.75 Vdc
Varies 0 to 4 Vdc with
Range of Light
Control
Fuse F-1
Power Supply Board or Battery
Pack
Amplifier Circuit Board
Amplifier Circuit Board
Amplifier Circuit Board
a.
b.
c.
Connect power sources.
Turn instrument ON.
If inopera-
tive, disconnect power source.
Conduct a visual check.
Remove the panel from its case,
place it upside down.
Check the fuse F-1 (8) on the
power supply board (9).
Check each plug, connector and
circuit board for proper connection.
Use your nose as
well as your eyes to locate possible burn areas.
With VOM in ohms mode,
check continuity of switches and
connections for malfunctions and open circuits.
4-5
