Sample Troubleshooting Problem

Sample Troubleshooting Problem To show how troubleshooting documentation is used to isolate faults, this sample problem is provided with corresponding fault analysis procedures by using samples of fault-isolation materials previously cov- ered in this chapter. The sample problem and asso- ciated fault analysis procedures are based on a fault revealed during SMT W-1. It is emphasized that these are suggested troubleshooting procedures and are not meant to preclude or remove judgment from the technician. For the sake of clarity, this problem is shown as separate steps. Refer to table 1-5 as you solve this problem. 1. Prior to the hypothetical fault, it is assumed that all turn-on procedures and preliminary test steps have been accomplished with no apparent malfunc- tions indicated. No PERMISSION TO TEST indica- tion is observed at the radar set console (RSC). 2. After verification of all test setups, the test coordinator then refers to the FAM for SMT W-1, which lists all SMT response steps (column 1) and the associated functions that are tested (column 2). 3. From columns 3 and 4, the sources and inter- mediate units can readily be determined. 4. Column 5 lists related SMTs. 5. Column 6 lists SFD figure 12-14.1 as the reference for the permission to test the function. By using the available reference material, the test coordi- nator can proceed to column 7 and implement the sug- gested fault-isolation procedures. 6. In column 7, step 4a, C-TASC (a computer diagnostic program) is used to determine if logical output voltages are being (1) generated at the radar data processor (RDP), and (2) transmitted to the radar set console (RSC). The succeeding fault-isolation pro- cedures listed in the FAM are then accomplished as required until the casualty is found or isolated to an equipment. If the preceding problem had arisen at any time other than during a scheduled test, the system FID (see table 1-3) and/or the FCS function directory (see table 1-4) could have been used. When the FID is used to facilitate solutions of problems encountered during normal operations or weapons system exercises other than scheduled test- ing, the faulty indication is identified and located in the Indicator column for the associated equipment listed in the Equipment column of table 1-3. Using the same hypothetical fault described above, refer to table 1-3 and locate the RSC in the Equipment column and PERMISSION TO TEST in the Indicator column. The applicable SFD and FAM may then be refereed to for trouble analysis. At the discretion of the test coordi- nator, the equipment may be setup as required in the referenced FAM, and the associated trouble analysis procedures accomplished as described in the above paragraphs. Where there is no readily identifiable in- dicator for a given function, reference maybe made to the SFD to cross-reference the applicable SFD. Equipment Troubleshooting Documentation Equipment operating procedures (OPs) contain a wealth of documentation to enable the rapid localiza- tion of faults that have been traced to a particular piece of equipment. The documentation includes (but is not limited to) fault logic diagrams, signal-flow diagrams, pyramid diagrams, relay and lamp indexes, and relay lamp ladder diagrams. In addition, mainte- nance turn-on procedures, shown in table 1-6, are provided for energizing the equipment. These pro- cedures contain references to troubleshooting docu- ments that are to be used if a given step of the procedure cannot be performed satisfactorily. 1-16