TM 11-5805-386-34/NAVELEX 0967-466-1020
a. Trouble On All Channels.
Corrective action
Malfunction
Probable cause
a. Check .25 AMP fuse; replace, if defective.
a. Fuse 1A4 F1 open.
1. No operation
b. Check contacts of switch for continuity;
b. INT-OFF-EXT switch
on internal
replace, if defective.
nor exter-
defective.
nal power.
a. Set power switch to INT.
a. Power switch not in
2. No operation
INT position.
on internal
b. Clean
battery
contacts.
b. Corroded battery con-
power; nor-
tacts.
mal opera-
c. Replace batteries.
c. Weak or dead batteries.
tion on ex-
d. Set power switch to INT and check contact
d. Power switch defective.
ternal pow -
continuity; replace switch, if defective.
er.
a. Turn control clockwise.
a. NIGHT ALARM control in
3. NIGHT ALARM in-
OFF position.
operative.
b. Set control to LOUD, activate a SERVICE
b. NIGHT ALARM defective.
REQUEST indicator, and check that
voltage lcross NIGHT ALARM indicator
terminals is 5.4 Vdc 1; replace
NIGHT ALARM indicator, if defective.
c. Activate a SERVICE REQUEST indicator
c. Common printed wiring
and check for 6.4 Vdc 1 at terminal
board 1A4A2 defective.
E3 of common board 1A4A2; if voltage
is not present, replace common
board 1A4A2.
d. If E3 voltage is present, but there is
d. NIGHT ALARM control
no voltage at NIGHT ALARM indicator
defective.
terminals, replace control,
a. Press SEIZE pushbutton and check
a. Defective SEIZE push-
4. 570 Hz acknowledge
continuity: replace, if defective.
button.
tone not heard
b. If signal is not present at test point
b. Seize tone oscillator
after pressing
TP7 on common module, check capacitor
not working.
SEIZE and ACCESS
1A4C3 for short and inductor 1A4L2
pushbuttons while
for open; replace, if defective. If
connected to
they are not defective, replace
remote switch-
common board 1A4A2.
board.
c. If signal is present, check dc voltage
at terminal E9 on common board 1A4A2; ,
if voltage is not present, replace
common board 1A4A2.
a. Replace keysender and oscillator
5. Single tone heard
assembly 1A4Al in common module.
oscillator defective.
when keying
b. Replace keysender and oscillator
b. Keysender pushbuttons
digits from key-
assembly 1A4A1 in common module.
defective.
sender.
Replace keysender and oscillator
Keysender pushbutton
6. One digit of key-
assembly 1A4A1 in common module.
defective.
sender provides
no tone or single
tone output.
a. Check for +3.0 V at S10-1 on keysender
a. Defective wiring in VR
7. No DTMF tone out-
1A4A1A2.
circuit.
pute occur; all
b. Check for +6.4 V l t E12 (W-R wire with
b. Defective keysender and
other operations
any key depressed and for 0.75 V p-p
oscillator assembly.
normal.
DTMF tones at E15 (W wire) with each
key depressed. If l ny voltage is not
. present, replace keysender and
oscillator assembly 1A4A1.
8. 2600-Hz release
a. RELEASE pushbutton
tone not gener-
defective.
replace. if defective.
ated when RELEASE
b. Release oscillator
b. If signal is not present at test point
pushbutton on
defective.
TP6 on common module, check capacitor
2-14
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