Technical Product Manual - DCT1900Maintenance, Fault Finding ProceduresMaint-DCT1900/R8/mw 6-1© 2000-2005CHAPTER 6Fault Finding Procedures6.1 IntroductionThese fault finding procedures are designed to help maintenance personnel locate and eliminatefaults in the shortest possible time. The fault finding extends to the level of a replaceable part(DTU, SPU, power supply unit, etc.). Although cabling and connection errors are not covered,suggestions will be given to check these items when the fault is presumed to be introduced bythem. The basic assumptions for the fault finding are:z Only one fault at a time.z The fault is persistent (not intermittent).z Fault is not due to cabling or bad connections.The execution of the following steps will avoid unnecessary fault finding:z Analysis of the fault symptoms.z Visual inspection of the system (cabling, connections, power cords).If these steps do not solve the fault, the flowcharts given in Paragraph 6.4 can be used.6.2 Symbols used in the Flow ChartsQuestionInstructionReferencesFlowQuestion?1234This symbol contains a question with two or three possibleanswers being "Yes", "No", or other Text.Inputs are points 1 or 4 and outputs are points 2 or 3 or 4.This symbol contains an instruction for the maintenanceengineer.This symbol is used as a starting point for a procedure (e.g.START), as a reference to another flowchart, or to end aprocedure (END).This symbol is used as a reference within one flowchart. Thiscan be to a part of the flowchart on another page (e.g. A or B)or to a part of the flowchart on the same page (e.g. 1).Arrows indicate the normal flow.
