TM 9-6625-1754-14
SECTION VI. MAINTENANCE
Remedy
Probable Cause
Symptom
22. Parts and Replacement
AC voltage ranges-continued
All the resistors and component parts of the
X1K Multiplier
Replace
X1K A-C votlage
range inoperative.
resistor, R25
multimeter are protected by the overload protec-
(Unit functions
tion system described in paragraph 6g. There are
normally on X 1,
conditions under which parts may become defec-
X10, and X100 AC
tive and need replacement. Consult table 12 for
voltage ranges.)
troubleshooting procedures and figures 12 and 13
DC voltage ranges
All DC voltage ranges X 1 Multiplier
Replace
to find and identify any suspected defective parts.
resistor, R34
inoperative.
The multimeter cover is removed by rotating
X 10 DC voltage range X 10 Multiplier
Replace
the slotted screwheads, on the outside of the
inoperative. (Unit
resistor, R28
hinges to the right and left of the carrying case
functions normally
handles, a quarter turn. This will permit separation
on X 1 DC voltage
range but not on
of the hinge halves and removal of the cover.
X10, X100, or X1K
ranges.)
Table 12. Troubleshooting Chart
Replace
X100 DC voltage
X100 Multiplier
Symptom
Probable cause
Remedy
resistor, R27
range inoperative.
General
(Unit functions
Replace
Unit totally inopera-
1. 10-amp fuse,
normally on X 1 and
F1
tive
X 10 DC voltage
2. Protection re-
Reset
ranges but not on
lay is discon-
X100 or X1K
nected. (If re-
ranges.)
lay will not re-
Replace
X1K DC voltage
X1K Multiplier
set, check for
range inoperative.
resistor, R26.
weak D cell.)
(Unit functions
AC voltage ranges
normally on X 1,
All AC voltage ranges
Replace
Detector assem-
X10, and X100
inoperative.
bly, A2
ranges).
X 10 AC voltage range
Replace
X 10 Multiplier
Search ohmmeter
inoperative. (Unit
resistor, R54
Replace
Search ohmmeter in-
Transistor assem-
functions normally
bly, A1
operative. (Digital
on X 1 AC voltage
ohmmeter func-
range but not on
tions normally).
X10, X100, or X1K
Replace
Search ohmmeter can- D cell
ranges.)
not be set at in-
Replace
X100 AC voltage
X100 Multiplier
finity (∞) on X1,
range inoperative.
resistor, R55
X10, X100, and
(Unit functions
X1K ranges.
normally on X 1 and
Replace
Search ohmmeter can- 6.75 Mercury
X10 AC voltage
not be set at in-
battery.
ranges but not on
finity (∞) on
X100 or X1K
X10K and X100K
ranges.)
ranges.
