ALTERNATIVE TROUBLESHOOTING TECHNIQUES

TM 11-7035-203-23

4-6. ALTERNATIVE TROUBLESHOOTING TECHNIQUES

When a failure causes a symptom which is not covered in the symptom index or not

corrected by the troubleshooting procedure in the flow chart, you must try

alternative techniques.

a. Understand Principles of Operation. Sometimes the symptom may have no

specific procedure given to troubleshoot it. When this happens, remember that the

equipment always operates the same way. By comparing the faulty operation with

expected or normal operation you may find the cause of the failure and be able to

fix it.

b. Check the Circuits. All electronic equipment uses circuits to route power

through the components. Any break in continuity will cause some type of failure.

By running continuity checks on suspect circuits you may find the cause of the

failure. Use the schematic diagrams in appendix D to check the circuits in this

equipment.

c. Check Past Maintenance Records. If the unusual failure occurred before, it

should appear in the maintenance records for the equipment. The records should

also tell you how the failure was corrected. Use the same fix this time.

d. Trial and Error Repair. Usually trial and error repairs should be avoided.

They are costly and can induce additional symptoms. However, when your experience

with the equipment leads you to suspect a definite cause, you should try the repair

as a last resort before shipping the equipment to depot for maintenance.

4-7. TROUBLESHOOTING PROCEDURES

The troubleshooting procedures are arranged as flow charts. The charts consist of

background information, specific instructions and decision points. Symbols (table

4-1) are used to organize the charts and guide you through a step-by-step trouble

isolation procedure for each known failure symptom.

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