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Course Notes:

Work Safety Precautions

General Warnings

• Don’t be in a rush – is it under warranty – if it is the problems not yours.
• Document what you do.
• Look to protect yourself and the equipment.

Electrical Precautions

• Pull the plug – you can replace computers – but you cant replace a human life.
• Disconnect all 240V attached to machine.
• Not just turned off – explain active lead to front of computer (show).
• Areas that are out of bounds.

1.       Inside the power supply.

2.       Inside monitor.

3.       Both should be fixed by qualified technicians – explain complexities of monitors (high voltage – specialized repairs – difficult to adjust without special equipment.

• Watch out for components left inside case – screws – screwdrivers etc. – these can cause short circuits and blow up components.

Mechanical Precautions

• If possible – have a large work area.
• Minimise components falling to floor and getting lost.
• Plenty of light – components and cable fittings are small – needs plenty of light to see what you doing and that they are being connected properly – Get a torch if necessary.
• Don’t tighten screws too tight.
• Use the right screws.
• Don’t use screws longer than 1/8 inch in the side of mounting drives.
• Watch out for sharp edges – especially poor quality cases – razor sharp.
• You can also cut overhanging wires with case edges – beware.

Data Precautions

• Back up your data – even on simple installations – even if done a hundred times before.
• Back up especially on upgrades – computer worth $2000 but data on the computer might be worth many tens of thousands to replace (if it can be).
• Make sure you have a bootable floppy.
• If you are working on a network make sure you have a bootable floppy with network drivers so that you can access the network.
• Make a copy of the CMOS setting before you work or change anything.
• If the computer is working – make sure everything opened is saved – then shut it down properly.

Electrostatic Discharge Precautions.

• Explain the concept of static electricity.
• Static kills components – it destroys instantly – it is a high voltage – most computer components are a low voltage.
• Work in a static-safe area – OR – use ground straps (see diagram)
• If you can’t work in antistatic area - ground yourself before touching anything.
• A good place to ground yourself is on the computer power supply case.
• Beware of working in carpeted area – some shoes generate more static than others – some clothes have the same effect – air conditioned buildings are more prone to it – beware of walking around in nylon socks and then touching components.
• Commercial wrist straps have built in resistor – safeguard against touching 240V or other live power sources.
• Handle components by their edges.
• Avoid touching pins, connectors and edge strips - explain oils from fingers can damage the connector strips.
• Store components in antistatic bags.
• Don’t use this material on the base of test beds because it is conductive.

Safety with Children

• Don’t leave computer with cases off around children
• This can apply to some adults

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