Section IV. TROUBLESHOOTING - TM-9-2320-366-20-10163

TM 9-2320-366-20-1

Section IV. TROUBLESHOOTING

2-10. INTRODUCTION TO LOGIC TREE TROUBLESHOOTING

This section contains step-by-step procedures for identifying, locating, isolating, and repairing equipment malfunctions.

This manual cannot list all malfunctions that may occur, nor all tests or inspections and corrective actions. If a

malfunction is not listed or is not corrected by listed corrective actions, notify your supervisor.

2-11. TROUBLESHOOTING INSTRUCTIONS

Page Layout. Troubleshooting procedures are divided into logic tree pages and test pages.

(1) A logic tree page is always a left-hand page, facing the test page on the right. The logic tree page provides

the sequence of steps required to isolate a fault to a failed component. All critical information for decision

making is on the left-hand page. Each logic tree page contains the following information:

(a) INITIAL SETUP - This box is located only on the first logic tree page of a fault. INITIAL SETUP lists

tools, materials, references, personnel, and equipment needed to troubleshoot the fault.

(b) KNOWN INFO - This box is located in the top left-hand column. KNOWN INFO lists conditions and

information that will eliminate specific components as the cause of the fault.

components that could cause a fault are listed in the POSSIBLE PROBLEMS box. The first component

listed in the POSSIBLE PROBLEMS box is the one that will be tested at that step in the logic

sequence. When one of the components is tested and found to be operational, it is entered at the

bottom of the KNOWN INFO box as OK.

(d) QUESTION - Each question, located in the middle column, refers to the first possible problem listed

in POSSIBLE PROBLEMS. If the answer to the question is YES, proceed to the next step. If the

answer is NO, follow the NO arrow to obtain directions for correcting the problem. If the step contains

a WARNING or CAUTION message, a small shadow box is printed above the question. Text for

WARNINGs or CAUTIONs is on the following right-hand page.

(e) TEST OPTIONS - This box is located in the top right-hand column. TEST OPTIONS lists tests available

for testing parts suspected of failing. When the TEST OPTION is a VOLTAGE TEST, the voltage

values listed are nominal values for a 12/24 VDC system. Some variation from these values should

be expected. When the TEST OPTION is a CONTINUITY TEST, the expected reading is one of low

resistance. If high resistance is noted, further testing should be performed to determine the cause.

(f)

REASON FOR QUESTION - This box is located directly below TEST OPTIONS. It explains the purpose

for the question in the middle column.

(2) A test page is always a right-hand page, facing the logic tree page on the left. The test provides detailed

instructions for testing the first component listed in the POSSIBLE PROBLEMS box. This test will also

provide an answer for the question in the middle column. Note the arrow connecting the test on the right-

hand page to the REASON FOR QUESTION. When possible, illustrations are included to provide visual

details. Notes contain additional information for testing.

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