Section IV. TROUBLESHOOTING PERMANENTLY CONNECTED CIRCUITS AND EQUIPMENT

TM 11-5895-878-14&P

NOTE

(b) Special tests on circuits or equipment.

Refer to site cable run drawings for

IDF to equipment cabling details.

(10) Advise the CCO, SCCO, or ICO when:

b. Change cross-connection or make new

(a) Any circuit has been restored or rerouted

connections on the associated IDF's (paras 2-3 through

over new facilities and must be tested from end-to-end.

2-9) to obtain the desired jack appearances and mux,

(b) A service will not be able to start on date

cable or VFCT assignments as necessary.

and time specified in the TSO.

c. Record cross-connections on circuit record card.

d. Perform the necessary in-house equipment

4-12. Procedure for Changing and Building Circuits

tests.

a. Patch around the in-house portion of the

e. Remove patches or plugs installed in (a) above.

existing circuit (fig. 3-4), or terminate the circuit legs on

f. Perform the necessary QA station-to-station

the line side of the patch panels with 600 ohm terminal

tests (para 3-20).

plugs.

Section IV. TROUBLESHOOTING PERMANENTLY CONNECTED CIRCUITS AND EQUIPMENT

refer to the "Trouble Symptom" column in the chart.

4-13. Use of Troubleshooting Charts

Perform the checks and corrective measures indicated

Troubleshooting of this facility is based upon

in the "Check and Corrective Maintenance" column to

malfunctions that may occur during normal operation of

locate and clear the trouble.

the equipment in the system. When a trouble occurs,

4-14. Troubleshooting Chart, Major/Minor Alarm Panel

(fig. 4-1)

Item

Trouble Symptom

Probable trouble

Check and corrective maintenance

No audible tone from audible

a. Tellite has been depressed, locking

a. Check for trouble as indicated by

alarm panel with a Tellite

out audible tone.

Tellite.

Illumination.

b. Gnd from alarm panel not being ex-

b. Remove the appropriate cross-connect.

tended to audible alarm panel.

from IDF and check for ground from

alarm panel output on the IDF block.

(1) If ground is found, check for -48 vdc

on the audible alarm input lead. If

battery is not present replace the

patch and check the operation of

the audible alarm panel (para 4-17).

(2) If no ground is found, remove the

connector from rear of alarm panel.

Make a continuity check from pin 91

of the connector (cable end) to the

IDF. After check is satisfactorily

completed, replace the cross-

connection patch cord.

c. Gnd not being extended through

c. If no ground is found on pin 91 it will

alarm panel.

be necessary to remove the alarm

panel from the bay to allow access

to the component parts. With the

top and bottom covers removed

make a continuity check, using a

VOM TS-352 or equal, from the pin

number that corresponds to the

illuminated lamp to Tellite pins NC1

and COM1. Refer to appendix D,

symbol number SW3, for Tellite

location. If continuity is obtained on

COM1 but not NC1 this indicates a

defective Tellite.

NOTE Care must be taken to

ensure that the (+) lead of the VOM

is connected to the corresponding

pin 1-45. This will forward bias the

diode in the circuit thus ensuring a

valid VOM reading.

4-5