TM 11-5805-689-14
12.0. Troubleshooting Chart
described in Chapter IV, paragraphs 11.4 through
11.10 above.
Before using the following chart, perform the checks
Probable cause
Symptom
Corrective action
(1) Cannot contact the switching
No seize tone being transmitted by
Attempt to send seize tone from a
the Converter
center b y d e p r e s s i n g t h e
different channel. If OK, replace
SEIZE pushbutton and channel
defective channel module. Check
ACCESS pushbutton
field side terminations on binding
posts (on back of the unit). Check
wiring on seize switch.
(2) Cannot release from the Converter
Attempt to send release from a
No release tone being transmitted by
to the switching center
the Converter
different Channel. If OK, replace the
defective channel module. If not
OK, check wiring to release switch.
Check battery connection. If still
bad, replace the common module.
Possible bad latch circuit
Replace defective channel module
(3) Servicing request indicator (SRI)
Borken wire to SRI and N/A
Check wiring to the SRI and N/A
doesn't function on one par-
ticular channel. Night alarm
(N/A) does not indicate
request-for-service.
Replace
keysender
(Refer to
(4) Cannot break dial tone when
Possible faulty keysender
dialing digits
Check wiring to ACCESS switch. Try
Possible broken wire to channel
different channel. If OK, replace
ACCESS switch
common module.
Replace defective channel module.
Possible faulty DTMF tone gate
Replace defective common module.
Possible faulity DTMF oscillator
circuit
Replace defective channel module
Possible faulity latch circuit
(5) Cannot cancel SRI or N/A by
d e p r e s s i n g ACCESS push-
button for a particular channel
Replace defective channel module
ACCESS pushbutton not clearing
(6) 570 Hz acknowledge tone is still
latch
heard in headset after ACCESS
Faulty latch circuit
Replace defective channel module
pushbutton is depressed
Replace defective channel module
Faulty ACCESS switch
(7) Operator u n a b l e t o t a l k t o
Faulty connection on two-wire port
Replace defective channel module
four-wire subscriber. Can hear
Bad connection on jacks in channel
Check wiring Replace defective
four-wire subscriber
module
module
Defective receiver
Replace headset
Voice gate circuit defective
Replace defective channel module
(8) Switching Center cannot hear
Replace common module
Defective interrupter circuit
ringback tone from the Con-
Defective 425 Hz oscillator
Replace common module
verter
Defective tone gate
Replace common module
Poor connection on field side ter
Check wires on binding posts for
mination
defective channels
13.0 Common Module Removal and
Keysender
common module and pulling forward until the
Adjustment Information
module has been completely extracted from the
C o n v e r t e r case.
1 3 . 1 The DTMF oscillator printed wiring board is
1 3 . 1 . 3 Remove the screws from the printed wiring
attached to the keysender. If adjustment of the
b o a r d securing the board to the module case.
k e y s e n d e r contacts is necessary, the printed wiring
13.1.4 Swing the hinged printed circuit board away
board will have to be removed from the keysender to
f r o m the module to expose the internal circuitry.
gain access to the keysender contacts. The
13.1.5 Carefully remove the six screws securing the
keysender is an integral part of the common module
c o v e r to the opposite side of the module.
within the CV-1919. The following procedures should
13.1.6 Remove the two keysender brackets by
be followed when disassembling the keysender from
r e m o v i n g the three screws securing the bracket to
the common module.
the keysender and battery case housing (on each
13.1.1 Remove the screws holding the common
side).
module to the Converter case (figs. 8 and 9).
13.1.7 The keysender is now free and can be
13.1.2 Slide the common module out of the Con-
removed by sliding it back out of the front panel of
v e r t e r by grasping the handle on the front of the
the module.
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