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Troubleshooting hardware components

Unit objectives Discuss the environmental factors that

affect computer networks and define physical and logical indicators of network trouble

Identify the function of common network tools

Discuss the science of troubleshooting

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Topic A: Introduction to troubleshooting Topic B: Introduction to common

network tools Topic C: The science of troubleshooting

Topic A

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Introduction to troubleshooting

To resolve most network difficulties – Identify physical indicators of network

trouble– Identify logical indicators of network

trouble

Error messages also play an important role in troubleshooting network difficulties

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Room conditions

Avoid harsh environments Make sure all power supplies are

properly grounded and the polarity is correct

Look for sources of magnetic fields Avoid static electricity Keep network components out of

locations that might flood Choose correct fire extinguishers Keep electronic components away

from cigarette smoke

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Placement of building contents

Ensure that network cabling systems remain clear of electrical power lines

Ensure that portable space heaters, hotplates, coffee warmers, and similar devices not in close proximity to network components

Avoid EMI Ensure that network cabling is routed

away from computer terminals

continued

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Placement of building contents

Review the local fire and electrical codes prior to cable installation

Check how and where the office personnel sit at their desks

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Computer equipment

Perform routine user maintenance on the systems in your charge

Avoid temperature extremes Ensure that the equipment is protected

if it must be exposed to a harsh environment

Avoid all liquids at the workstation

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Activity A-1 page 8-5

Handling environmentally caused problems

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Physical and logical indicators Network hardware

– Workstations and servers: enough CPU power, RAM and bus speed.

– Network adapters: wh/protocol?, wh/bus?, wh/connectors? LEDs: link, power, collisions.

– Cabling: “Lay of the wire”, kind o/cable. – Hubs: LEDs for data flow and collisions. – Routers: is the problem internal or external?– Switches: the book d/n mention switches, but

b/c they h/individual ports, errors c/b isolated to just 1 P2P link.

Error Messages– Hardware error messages: config, card seating – Software error messages: how widespread?

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Activity A-2 page 8-8

Discussing causes of network trouble:(2 troubleshooting scenarios.)

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Topic B page 8-9

Topic A: Introduction to troubleshooting Topic B: Introduction to common

network tools Topic C: The science of troubleshooting

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Network tools Crossover cable: connect like devices Hardware loopback: tests connectivity Tone generator: testing cables for “continuity”

over their length, ie, will the cable carry a signal for its length?

Fox and Hound: 2 parts: the fox sends a signal and the hound locates it. Tells you where a fault is

Cable tester: tests for continuity and gives you a wiring diagram so you can distinguish a patch from a crossover; also so you can see common wiring errors – split pairs, etc.

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Network tools Multimeter: More sophisticated and

versatile devices. Able to measure a variety of electronic output and characteristics: volts, ohms, resistance, continuity, etc.

Time domain reflectometer – TDR: This device is able to tell you where, along a length of cable, a fault lies, by measuring the time it takes a signal to travel the length of the cable, up to the point of the break, and then to return to the TDR.

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Activity B-1 page 8-11

Identifying network tools

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Topic C

Topic A: Introduction to troubleshooting Topic B: Introduction to common network

tools Topic C: The science(?) of troubleshooting

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Efficient troubleshooting

Basic troubleshooting skills Documentation Tools

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The DIReCtional troubleshooting model

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The DIReCtional troubleshooting model Define the problem

– Describe the problem– Determine the problem type– Specify the conditions– Try an immediate solution– Document everything pertaining to

the problem– Set expectations

Isolate the occurrence – Reproduce the problem: (if you can do this,

you usually can find the answer)– Classify the problem continued

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The DIReCtional troubleshooting model

– Reconfirm the problem– Document

Resolve the problem – Research the problem– Identify potential causes– Eliminate unlikely causes– Solve the problem– Repeat the solution– Document the resolution

continued

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The DIReCtional troubleshooting model

Confirm the resolution and expectations– Review case history– Confirm with your customer– Broadcast the solution– Document final findings

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Troubleshooting tips

Make sure the problem is not being caused by the operator

Ensure that all the devices are plugged in and switched on and that the wall outlet is supplying power

Ensure that the problem is not caused by software

continued

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Troubleshooting tips

Ensure that external indicators show peripherals are ready

Run diagnostic programs Remove the case and re-seat the

boards

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Troubleshooting software

Check whether the application or operating system has been recently upgraded, i.e., software changes.

Check whether you have made any hardware changes recently

Check whether the problem is common to all the systems

Check whether the problem is limited to one type of system

Check whether the problem is limited to one system

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Activity C-1 page 8-20

Discussing troubleshooting techniques

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Troubleshooting documentation

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Activity C-2 page 8-22

Discuss Troubleshooting Documentation– The documentation can be taken down in written

form, but electronic data lets you analyze the facts for trends and patterns.

– Minimum info for trouble report forms: DateContact (the person experiencing the problem)DescriptionSymptomsPriority

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Traditional tools

Screwdrivers Standard pliers Long-nose (needle-nose) pliers Nut drivers (or a small socket set) Tweezers Torx (spline) drivers Chip pullers Small flashlights Multimeters or

Volt-Ohm-Milliammeters (VOM)

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Sources of troubleshooting information

In-house documentation:– Your problem may already be documented

Vendor manuals:– preferably with technical information

Commercial publications:– Sites for PC config & repair– databases with settings, installation info, etc.

Bulletin boards and online services:– either by the vendors or independent

The Internet Associates and co-workers

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System diagnostics

Disadvantages of System diagnostics– Restricted availability– Limited range of tests (determined by

the vendor)– Limited to a specific system – Will not be able to test any of the

expansion hardware

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Third-party diagnostics and utilities

Advantages of third-party diagnostics and utilities – Range of support

not limited to only one system or model

– Available testswide range, covering most hardware/software

– Customized testing procedures – Other utilities

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Selecting Diagnostic Software Systems Supported:

– be sure yours is supported Available Tests:

– a wide range is good; software & hardware Testing Procedures:

– should be flexible and able to be configured Reporting Capabilities:

– should keep a log, be able to copy it, and preferably to parse it.

“Destructive” Tests:– be aware if you are using one; it may, e.g.,

write over the data on your hard drive

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Activity C-3 page 8-27

Identifying troubleshooting tools

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Unit summary

Learned about the environmental factors that affect computer networks and defined physical and logical indicators of network trouble

Identified the function of common network tools

Learned about the science of troubleshooting