Follow these steps to visually inspect cables and test the cables:

1. Examine the length of the cable for obvious damage, such as a cut or abrasion in the outer sleeve with further damage to the twisted pairs inside. A completely cut strand is an obvious problem, but the conductor inside the cable might be broken even if the insulator is intact. Any visible copper is an indication you need a new cable.
2. Inspect the RJ-45 connectors. In particular, look for exposed twisted pairs between the clear plastic connector and the cable sleeve or jacket. This indicates that the cable was assembled improperly or excessive force was used when pulling on the cable. The cable sleeve should be crimped inside the RJ-45 connector. Sometimes you can identify a nonconforming wiring scheme by noting the color of the insulation through the clear connector, but you should check the cable with a multimeter to verify its condition.
3. Next, verify that the retaining clip on the connector is present. When an assembled cable is pulled, this clip often snags on carpet or other cables, and breaks off. This results in a connector that's likely to become loose or fall out of the jack. Worse still, this connection might be intermittent. Some cables have boots to prevent the clip from snagging when pulled, but these boots can cause problems when seating the connector in the jack if the boot has slid too far toward the end of the cable.
4. Test your cables with a multimeter, and fill in Table 2. For each cable, you need to identify which pin at one end of a cable connects to which pin at the other end of the cable. To do so, you use the multimeter to systematically determine continuity between pins. For example, start with pin 1 of cable 1. First record the insulator color for this pin. Then check for continuity between it and each of the pins at the other end of the cable. Which pin connects to pin1? Record that information (insulator color and pin position) in the first row of the table. Then continue to the other pins and cables until the table is completed. What settings on the multimeter did you use when testing the cables?

Table 2: Pin connections for selected cables

Cable 1End AEnd BQuestions About the CablePin #Insulator colorPin tied to pin at End BInsulator colorPin tied to pin at End AIs the cable good or bad?

1

2

Wired with what scheme?

3

4

5

Is the cable a crossover or patch cable?

6

7

8

Cable 2Pin #Insulator colorPin tied to pin at End BInsulator colorPin tied to pin at End AIs the cable good or bad?

1

2

Wired with what scheme?

3

4

5

Is the cable a crossover or patch cable?

6

7

8

Cable 3Pin #Insulator colorPin tied to pin at End BInsulator colorPin tied to pin at End AIs the cable good or bad?

1

2

Wired with what scheme?

3

4

5

Is the cable a crossover or patch cable?