The Absolute Basics

Never think you don't know enough to start fixing - the bar is probably lower than you think!

Summary

Even though they may be handy at DIY, many people are hesitant to get into fixing electrical items because they think they don't know enough. In fact, very many faults can be seen with your own eyes. Even if you don't consider yourself handy, a logical approach and a bit of curiosity might get you further than you'd think possible.

Safety

You're probably here because you know that mains electricity can be lethal - congratulations! But electricity plays fair - if you learn to treat it with proper respect (which isn't hard), then it won't bite you. Just don't push your luck!

Screwdrivers and some other tools have pointy ends and can cause injury if they slip.

Minimum Skills and Knowledge

Here, we set out the minimum skills you need under the headings of Mechanical, Electrical and Logical.

Mechanical Skills

• You will need a set of screwdrivers, including both flat and cross-head, in several sizes. You can never have too many screwdrivers!
• Know which way to turn a screw to tighten or to loosen it. The simple rule is righty tighty, lefty loosey.
• Choose a screwdriver that's a good fit in the screw, especially if it might be tight.
• If you feel the screwdriver starting to slip in the head of the screw, press harder. If the screwdriver repeatedly slips you may damage the head of the screw and make it nearly impossible to undo.

Electrical Skills

Battery powered items are generally safe to work on but you need a good understanding (nevertheless, quite easily acquired) in order to work safely on mains items.

Battery Items

• Take care with cameras and flashguns in which the flash consists of a glass tube. These contain a capacitor which may retain suficient electrical charge to give you a nasty shock, long after the item is switched off.
• Treat lithium batteries with respect. Shorting the terminals together or physical abuse can create a serious fire hazard.

Apart from the above caveats, you can safely work on items powered by a battery or small solar cell.

It will greatly help to understand the most basic principles of electricity:

• Electricity can only flow if it can flow all the way around a circuit, from one battery terminal, through the works where it does something useful, and back to the other battery terminal. A switch in the "off" position or any break in the circuit will prevent the flow. This is known as an "open circuit".
• Electricity generally flows easily through metals and to some extent through water or anything damp. (These are called conductors.) Electricity cannot flow through most other materials (known as insulators) such as plastics, rubber, wood, glass, provided they're dry.
• Voltage (measured in volts) is a measure of electrical pressure, a bit like water pressure or air pressure in a tyre. All common types of battery (and small solar cells) only produce a few volts. Above about 50 Volts, electricity is potentially dangerous.
• Amps are a measure of the amount of current flowing through a circuit.

You also need to be aware of the following practical apects:

• If two wires touch which shouldn't, or a wire touches part of a metal case, this creates a "short circuit", offering very little resistance to the current. In the worst case, this may create a fire hazard.
• An item may stop working or work unreliably if there are loose connections, dirt or corrosion on the contacts in a plug or socket, or in a battery compartment.
• A simple multimeter is quite cheap and it's not hard to learn how to use. You can use it to test for an open circuit (no connection where there should be one) or a short circtuit (a connection where there's not supposed to be one). It's also easy to use it to test a fuse and to check for a weak or dead battery.