Section IV. TROUBLESHOOTING TECHNIQUES
Basic Troubleshooting Procedure.
Trouble Symptom. The basic troubleshooting procedure is an organized plan of action to help you repair
faulty electronic equipment rapidly and reliably. This systematic and logical troubleshooting procedure starts with the
trouble symptom. The trouble symptom lets you know that something is wrong with the equipment. So, you have to
analyze the trouble symptom as it affects the operation of the equipment. The trouble symptom provides clues that show
you where to look for the trouble.
Sectionalize. Once you have recognized the trouble symptom, the next step is to sectionalize the trouble.
Each piece of equipment is divided into a few basic sections. But to trace the trouble to a particular section, you must first
analyze and evaluate the trouble symptom to decide which section is giving trouble.
Localize. After you have found which section of the equipment is at fault, the next step is to localize the
trouble to a particular circuit or stage.
Isolate. After localizing, the next step is to isolate the faulty component either by making a visual inspection
or by taking voltage and resistance measurements. In this manner, you pinpoint the trouble to a bad component in a single
Repair. Correct the trouble by repairing or replacing components in the stage.
Check Operation. After repairing the trouble, check the operation of the equipment to make sure that it is
Troubleshooting with the Technical Manual.
General. This section explains how to use the technical manual (TM) when troubleshooting and performing
the various procedures listed in the manual.
Selecting the Proper TM. The Direct Support and General Support Maintenance Manual, TM 9-1240-XXX-34
series, should be selected when performing troubleshooting procedures. This manual is divided into two volumes for this
Volume I, contains troubleshooting procedures.
Volume II, contains maintenance procedures.
How to Troubleshoot (fig. 7-20). The following steps explain how to troubleshoot using the TM 9-1240-XXX-
34 series TM.
Do a visual check and list any faults on DA Form 2404 before making repairs. See Volume II, Chapter 3
for what to check for.
If you see any faults that may affect the checkout procedure, fix them now. This does not mean small
things like painting scratches.