Section IV. SYSTEM TROUBLESHOOTING WITH NO ERROR SHOWN ON ALPHANUMERIC

TM11-5830-263-20&P

SECTION IV

SYSTEM TROUBLESHOOTING WITH NO ERROR SHOWN ON ALPHANUMERIC

DISPLAY

CAUTION

BE SURE TO REMOVE POWER FROM THE MCS BEFORE DISCONNECTING OR

REMOVING AND REPLACING COMPONENTS AND/OR CABLES.

2.8.

TROUBLESHOOTING WITH NO ERROR MESSAGE DISPLAY

a. General

The procedures in step b below troubleshoot faulty equipment in VIS not indicated on the MCS

alphanumeric display. They apply whether trouble is in radio or intercom communication. If an

error message is displayed, refer to Section V. See Table 2-2 for the troubleshooting flowchart(s)

to correct the fault.

b. Troubleshooting the system

Perform the following steps in sequence, to ensure accurate troubleshooting of the equipment:

System Troubleshooting Chart, Table 2-2, lists symptoms of faults in priority order. Start with the

lowest test number on Table 2-2 that resembles the current fault. If a test number is skipped, it is

assumed that symptom has not occurred.

NOTE

Reference to "substitution of a VIS box with a known good one" in the troubleshooting

flowcharts refers to properly configured (Section III) and operationally verified

replacement equipment.

Table 2-2. System Troubleshooting Chart

Test

Corrective

Number

Symptom

Probable Causes

Measures

Vehicle master circuit breaker

Defective MCS.

See figure 2-39.

trips.

Defective power cable

assembly.

Defective vehicle wiring.

MCS alphanumeric display does a.

Power is turned off.

See figure 2-40.

not light when SYSTEM switch is b.

Defective power cable

in position other than OFF.

assembly.

System power fault.

Defective MCS.

MCS System Power Fault LED

Defective MCS.

See figure 2-41.

illuminates.

Defective highway cable

assembly.

Defective FFCS/RIT/MOS.

2-42