Section III. TROUBLESHOOTING - TM-11-7010-201-40-10039

TM 11-7010-201-40-1/ET821-AA-MMI-010/E154 MTS/TO 31S5-2TSQ73-2-1

Section III. TROUBLESHOOTING

3-6. Introduction . This section consists of general troubleshooting information for General Support maintenance

personnel. Troubleshooting the MTS consists primarily of performing the MTS self-test procedure (refer to TM 11-7010-

201-12) and performing continuity checks on cables and wiring harnesses.

NOTE

Intermittent failures may be caused by debris in the wire-wrap assemblies or a poor

cable connection. A close inspection and cleaning may correct the problem.

3-7. Wire Lists. Wire lists (see volumes 2, 3 and 4) are servicing aids for signal tracing and troubleshooting. They

provide descriptive data such as connector number, type of wire, wire groups, routing, shielding, logic, mnemonics, and

other information related to internal wiring. The MTS uses three types of lists - connector, string, and logic - to

completely document wiring and signals. The following paragraphs describe the content and structure of these lists.

a. Connector List. The connector list furnishes a listing of all connectors in the MTS in alphanumeric order with the

designated signal on each pin. Included in the list are terminal boards, ground blocks, and components mounted on the

connector assembly. These parts also have the signal designations on each pin identified. Nonwired connector pins are

also listed, whether unused, connected to spare circuits, or connected to spare OR

gates. A typical connector list example is shown in figure 3-1. Table 3-1 explains the connector list column headings.

b. String List. The string list provides the information necessary to identify the interconnections for a specific signal

designation. The list presents data according to signal designations which are given in alphanumeric sequence. The

string list is useful in isolating shorts, opens, and grounds. A typical string list example is shown in figure 3-2. Table 3-2

explains the string list column headings.

c. Logic List. The logic list contains equations arranged in alphanumeric order. Logic lists are provided for each

assembly containing digital circuitry. Specifically, the logic list shows the active elements, with the logic gates required to

perform specific functions. Supplementary information provided by the list includes the part number of the circuit card

containing the circuit elements, the specific circuit group used on the card, the location of the circuit card in the card rack,

significant test points, and a brief description of the function that each equation performs. A typical logic list example is

shown in figure 3-3. An explanation of the logic list is given in table 3-3.

d. Wire Information. Wire used to interconnect various cards and components within the MTS has identifying marks and

codes which define the type of wire to be used during repair. Figure 3-4 shows the various types of shield terminations

used in the MTS. Table 3-4 provides a list of the basic wire codes used to identify he different kinds of wire. Detailed

wire information can be found in the appropriate wire list.

e. MTS Wire List Index. An index to the various connector, string and logic lists for the MTS is provided in table 3-5.

3-3