TM 11-5805-424-15/NAVELEX 0967-220-9010/TO 31W2-2G-41
Section II. TROUBLESHOOTING AND REPAIR
corrective actions were taken and notify higher category
4-5. Troubleshooting
maintenance personnel. All symptoms in the chart are
obtained during normal operation, or during the
a. General. The troubleshooting chart. given in b
operator's daily preventive maintenance checks and
below is provided as an aid in localizing troubles in the
services and the organizational monthly preventive
MD-674(P)/G to parts (such as modules and printed
maintenance checks and services. If it is necessary to
circuit cards) authorized for organizational replacement.
check voltages or waveforms at a specific pin of a
Only those corrective measures are given which
printed-circuit card connector, remove the printed circuit
organizational maintenance personnel can perform. If
card and insert the adapter card in its place. Plug the
the measure suggested does not restore normal
printed-circuit card into the adapter card and check the
operation, troubleshooting at a higher category of
voltage or waveform.
maintenance is required. Note on the repair tag what
b. Troubleshooting Chart.
Item
Trouble symptom
Probable trouble
Check and corrective measures
No.
1
No indication on AC POWER
a. Defective 115/230V 3A fuse
a. Replace fuse.
indicator with AC POWER
switch set to ON; blower motor
b. Defective power cable
b. Check power cable; and replace
does not operate.
if necessary.
2
No indication on AC POWER
Defective AC POWER indicator
Replace indicator lamp.
indicator with AC POWER
switch set to ON; blower motor
operates.
3
AC POWER indicator lights with
Defective blower motor in power
Replace power supply submodule
AC POWER switch set to ON,
supply submodule (fig. 1-5).
and blower motor does not
operate.
4
All front panel indications normal,
a. Defective -15V 1-1/2A or +15V
a. Replace fuse.
no indication at LINE MONI-
1-1/2A fuse (fig. 3-1).
TOR jacks, and order-wire
b. Defective power supply 15
b. Check voltage at D.C. POWER
inoperative.
volts printed-circuit card
+15V and -15V jacks (fig.
assembly A15.
2-3); if incorrect, replace
assembly A15 (fig. 1-6).
c. Defective power supply 6 volts
c. Check voltage at D.C. POWER
printed-circuit card assembly
+6V and -6V jacks (fig. 2-3);
A14.
if incorrect, replace assembly
A14 (fig. 1-6).
d. Defective power supply sub-
d. Replace power supply submodule.
module (fig. 1-5).
5
No indication at LINE MONI-
Defective transmit section
a. Check for input data at pins J
TOR SEND jack, no order-
and K of assembly A12 con-
wire operation, and ALARM
nector; if not present, replace
indicator lighted.
assembly A12.
b. Check for fsk ,signal at test jack
J1 on assembly A18 through
A32; if not present, replace
MX-73(*)/G module (para
c. Check for fsk signal at test jack
J2 on assembly A18 through
A32; if not present, replace
assembly A18 through A32
(MX-73(*)/G printed-circuit
card).
4-4
