Nortel Networks DCT1900 manual Fault Finding Procedures, Symbols used in the Flow Charts

Technical Product Manual - DCT1900

Maintenance, Fault Finding Procedures

CHAPTER 6

Fault Finding Procedures

6.1Introduction

These fault finding procedures are designed to help maintenance personnel locate and eliminate faults 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 by them. The basic assumptions for the fault finding are:

zOnly one fault at a time.

zThe fault is persistent (not intermittent).

zFault is not due to cabling or bad connections.

The execution of the following steps will avoid unnecessary fault finding:

zAnalysis of the fault symptoms.

zVisual 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.

6.2Symbols used in the Flow Charts

Question

1

This symbol contains a question with two or three possible

4 Question? 2 answers being "Yes", "No", or other Text.

Inputs are points 1 or 4 and outputs are points 2 or 3 or 4.

3

Instruction

This symbol contains an instruction for the maintenance engineer.

References

This symbol is used as a starting point for a procedure (e.g. START), as a reference to another flowchart, or to end a procedure (END).

This symbol is used as a reference within one flowchart. This can 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).

Flow

Arrows indicate the normal flow.

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