Device Safety

Use these instructions as a starting point, but remember that every device is different. Keep an eye out for any possible safety hazards that might be unique to your situation.

• Plan your repair carefully. Try to anticipate potential hazards, and take steps to avoid them.
• If you feel unsafe performing any aspect of a repair, stop working and ask for help.
• Don't perform potentially hazardous repairs alone. In the event of an emergency, it's important to have someone on hand to help or call 911 (or 112 in the EU, or equivalent).

Never work on anything that is plugged in to a power outlet.

• The device should be physically unplugged, not just “switched off.”
• Whenever possible, remove the battery or batteries before beginning disassembly.

Big capacitors (the kind most likely to be dangerous) are usually cylindrical and look roughly like battery cells.

• Assume they are charged until you've confirmed they are discharged.
• Use an appropriate tool to discharge and/or ground large capacitors, while keeping yourself well insulated and at a safe distance.
• When discharging large capacitors, use only one hand, and keep the other hand behind your back or in your pocket. This prevents you from inadvertently completing a circuit with your second hand and creating a path for electric current to travel through your heart.
• Wear rubber-soled shoes.
• Wear eye protection. A stray spark can cause severe eye damage.
• Remove all rings, bracelets, necklaces, etc. before working on devices with large capacitors.

Large, mechanical devices such as bicycles or cars contain many moving parts that can pose a safety hazard, particularly when repairs are being performed.

• Any given part’s range of motion may change suddenly while you are working on it. Position yourself so that if a heavy or potentially dangerous part moves unexpectedly, you will not be injured.
• Wear protective gloves.

Printed circuit boards in older electronics may contain toxic heavy metals such as lead and mercury. Wash your hands thoroughly after you finish working, and before you eat. Don't eat or drink while handling electronic components.

Protect yourself and others from injuries. Before performing repairs on any device, do the following:

• Wear gloves. Sharp edges can cut your hands.
• Wear safety shoes. Accidents are often caused when dropping things, especially on feet that are not protected.
• Avoid loose clothing that could get caught in a device while you are repairing or while it is operating.
• Remove all jewelry when working on a device including watches, rings, etc.
• Tie long hair back.
• Wear safety glasses to protect your eyes from flying debris.
• Use proper tools that are clean and in good working condition.
• Have ample light in your work area.
• Be careful when handling access panels or any other components that may have sharp edges.
• Avoid placing hands in any area that has not been visibly inspected for sharp edges or pointed screws.
• Be sure that the work area is clean and dry from water and oils.
• When working with others, always communicate with each other.
• Always ask for help when moving heavy objects.
• Always use your leg muscles and not your back muscles when lifting heavy objects.

Look out for your fellow fixers! Make note of any steps that present a possible hazard—or that could become hazardous if performed inattentively or incorrectly—and warn your readers accordingly with one or more “Caution” bullets.

To add the “Caution” bullet to any specific steps that could pose a safety hazard:

1. When editing the step, click the black bullet next to your text in order to display the list of special bullets.
2. Select the “Caution” bullet.
3. In the accompanying text, clearly explain the nature of the hazard. Include detailed steps the reader should take in order to complete the task safely.
4. Save your work when you are finished.

For especially hazardous procedures, consider adding a warning in your guide’s introduction as well.

Some repairs require soldering, which may be intimidating for first-time fixers. Soldering can be both safe and fun, provided a few basic safety guidelines are followed.

Protect your lungs. Solder fumes can be toxic. At the very least they will irritate your lungs if inhaled, and may aggravate certain medical conditions such as asthma.

• Work in a well-ventilated area.
• Keep your head to the side of your work, rather than directly above.

Protect your skin.

• Use lead-free solder.
• Hold wires and solder with tweezers, or wear protective gloves. Don't use your bare hands.
• Don't touch the tip of the iron. (If it's hot enough to melt solder, it's more than hot enough to burn you.)
• Wash your hands after finishing your work.

Protect your eyes. Solder can “pop” and “spit” unexpectedly, so wear safety glasses when soldering.

Protect against heat, fire, and other hazards.

• Solder only on heat-resistant surfaces and materials. (Good: A piece of drywall. Bad: A ream of paper.)
• Keep your workspace tidy, and clear it of any flammable objects before you begin.
• Set the soldering iron down only on the iron stand.
• Never leave a hot soldering iron unattended.
• Keep a fire extinguisher nearby, and make sure you know how to use it.
• Don't eat or drink while soldering.

Protect the environment. Don’t throw lead solder, or sponges contaminated with lead solder, into the trash. Put them in a sealed container and take them to your local household hazardous waste disposal facility. If circuit boards or other electronic components are beyond repair, recycle them responsibly.

Do not attempt to disassemble or repair older, CRT televisions or computer monitors. CRT displays contain potentially lethal high-voltage capacitors, glass-walled vacuum tubes that can implode violently if mishandled, and large quantities of lead.

• You can recognize CRT displays primarily by their bulk: unlike modern flat screen LCD or plasma displays, which tend to be quite thin, CRTs are typically about as thick as they are wide.
• Leave CRT display repairs to an experienced technician.

Modern flat screen displays are much safer to service than older, CRT-type TVs and monitors. However, there are a few potential hazards to be aware of before you service one of these displays.

Unplug the TV from the power outlet before you begin work. This should go without saying for all electronic devices, but flatscreen displays contain power supply boards with large capacitors that can be particularly dangerous when charged.

Before touching any other internal components, disconnect the power supply from the main board.

• The power supply usually looks like a circuit board with a series of cylindrical capacitors that look roughly like battery cells.
• Avoid touching or prying near the capacitor leads unless you have verified that they are fully discharged.

Use extra caution with CCFL-backlit displays. Some pre-2010 flat screen displays used cold cathode fluorescent lamps (CCFLs) containing mercury. CCFLs look like long, tube-shaped fluorescent lights, usually placed behind or to the sides of the display. If broken, they may leak small amounts of mercury, which is very toxic. If you accidentally break a CCFL bulb:

• Do not touch any glass shards or spilled liquids with your bare hands.
• Wear protective gloves, and clean the area with a damp rag.
• Keep the area well-ventilated.
• When finished, wash your hands thoroughly.
• Be sure to put any mercury-contaminated shards or rags in a sealed container and dispose of them responsibly.

Microwaves are among the most hazardous appliances to repair. They contain large, high-voltage capacitors capable of delivering a fatal electrical shock, and can also leak harmful levels of radiation if damaged or reassembled improperly.

• If you're unsure about what you're doing, get expert help before you begin.
• Do not touch any internal components or wiring until you have verified that all high-voltage capacitors are discharged.
• Never operate a microwave that looks damaged or imperfectly repaired. Be especially wary of damage to the door, hinges, latches, or seals.

Fixing motor vehicles like cars and trucks can be very rewarding, but also comes with more hazards than a typical smartphone or laptop repair. If you choose to perform a motor vehicle repair, take appropriate precautions.

Never work under a vehicle that is supported only by a jack. The purpose of the jack is to lift the car off the ground, not to hold it in place! An untimely jack failure can easily kill you. Secure your vehicle with jack stands, or use ramps to raise and lower it safely.

Choose secure jacking points. These vary from one vehicle to the next, so proceed with caution—a jack or jack stand placed under an oil pan or a power steering line won't protect you, and will likely damage your vehicle as well. If in doubt, consult your vehicle's service manual, or get help from an expert.

Park the vehicle on firm, level ground before raising it. Jacks, jack stands, and ramps are designed to be used on hard, level surfaces like concrete and asphalt. Never attempt to raise a vehicle that's parked on a slope or an unstable surface like grass, dirt, or gravel.

Secure the wheels and drivetrain. Raising cars and trucks can cause them to roll unexpectedly, even on a level surface. Before jacking up any vehicle, shift into Park (or first gear, if you have a manual transmission). Make sure the engine is off, and set the parking brake. Then, block the wheels opposite the jack with wheel chocks, bricks, or large wooden wedges.

Always disconnect the battery before beginning repairs. Battery type and location varies by vehicle, so consult your vehicle's user manual for exact instructions.

• There is a risk of electric shock if the battery terminals are handled incorrectly or inattentively. Observe the safety guidelines in your user manual, and get help if you aren’t sure what to do.
• Never work on a vehicle with the motor running. Even at idling speed, engine belts and fans can cause serious injury. Cooling fins rotate fast enough that they can be practically invisible at the edges, and can easily catch you off guard. There may also be electrical hazards at the alternator, spark plug wires, and other areas. If you need to start the engine, stay well clear of the engine bay, and make sure all four wheels are firmly on the ground.

Protect your eyes and skin. A pinched finger or a stray splash of brake fluid can leave you seriously, even permanently, injured (and bring your project to a halt, to boot). Wear protective gloves and safety glasses at all times.

Protect your lungs. Automobiles contain an abundance of toxic substances, from brake dust to gasoline fumes. Work in a well-ventilated area, and wear a mask or respirator if appropriate.

Protect your pets. Don't leave automotive fluids—particularly coolant or antifreeze—lying around for your pets to find. Antifreeze commonly contains ethylene glycol, a toxic compound which nevertheless gives off a sweet odor that is appealing to many animals. Keep your coolant or antifreeze containers sealed, and transfer used fluids to a sealed container immediately after draining them from your vehicle.

Use the right tools. Taking shortcuts by trying to “make do” with a less-than-perfect tool can turn even a simple repair into one fraught with hazards, for both you and your vehicle. If you don't have the right tools, get them! Many auto parts stores have tool checkout programs that can help you complete a repair properly, inexpensively, and safely.

Observe local laws, and protect the environment. Used automotive fluids such as motor oil, gear oil, transmission fluid, brake fluid, power steering fluid, and coolant (antifreeze) must be disposed of responsibly—along with any rags, paper towels, or filters that have been contaminated by these substances. Take them to your local household hazardous waste disposal facility in a sealed container. Never pour used automotive fluids down the drain or into the street.

Lithium-ion batteries power nearly all modern mobile devices. While they are not normally dangerous, they do store a large amount of energy—energy which can cause serious injury if released suddenly.

Never puncture a battery. Don't pry at batteries with screwdrivers or other sharp tools. A damaged battery can rapidly heat up, catch fire, and even violently explode.

Don't bend or deform batteries excessively. It's normal for glued-in batteries, like iPhone and iPad batteries, to deform slightly when removed. However, excessive bending could rupture a cell and cause a fire. Use caution and try to keep any deformation to a minimum.

If you notice any battery smoking or swelling to large size, stop working and back away.

Digital camera flashes are powered by capacitors capable of delivering severe electric shock.

Don't be fooled! They may look innocent, but even small cameras contain capacitors that pack a wallop.

• The capacitor stores a charge drawn from the camera's battery. Be sure to remove the battery before you open the camera or attempt to discharge the capacitor.
• After opening a camera, avoid touching any internal components until you have verified that the capacitor is safely discharged.

Before disassembling or servicing any air compressor:

• Unplug the power cord.
• Open the bleed valve on the main tank to release any compressed air. Never work on an air compressor while components are under pressure.
• Never attempt to puncture air tanks with sharp objects or tools.

Proper lubrication is crucial to air compressor functionality and safety. When working on air compressors:

• Do not over lubricate.
• Use the correct oil or lubricant for your model. Avoid low flash point lubricants, which have the potential to ignite during operation and cause a fire or explosion.

A typical PC power supply contains capacitors large enough to deliver a significant electrical shock.

• Never work on a power supply that is plugged in.
• After unplugging the power cord, press and hold the PC's power button for about 5 seconds. In some cases this will help drain capacitors that might otherwise have retained a charge.
• After unplugging the power, wait 10 minutes before disassembling the power supply. Capacitors used in PC power supplies typically lose any remaining charge a short time after being unplugged.
• Nevertheless, assume all large capacitors are charged unless you have confirmed otherwise. Safely ground or discharge all large capacitors before handling internal power supply components.

Know where and how to turn off electricity to a device when performing a repair. For example: know the places of plugs, fuses, circuit breakers, and cartridge fuses in the home. Label them if necessary. If a specific diagnostic check requires that voltage be applied, reconnect electricity only for the time required for such a check, and disconnect it immediately thereafter. During any such check, be sure that no other conductive parts come into contact with any exposed current-carrying metal parts. When replacing electrical parts or reassembling a device always reinstall the wires back on their original terminals according to the wiring diagram. Check to be sure that the wires are not crossing any sharp areas, are not pinched in some way, are not between panels, and are not between any moving parts that may cause an electrical problem. Some additional safety tips:

• Always use separate, grounded electrical circuits for each device.
• Never use an extension cord for major appliances that aren't able to handle the voltage.
• Be sure that the electricity is off before proceeding with a repair.
• Never remove the ground wire from a three-prong power cord or any other ground wires from the device.
• Never bypass or alter any device switch, component, or feature.
• Replace any damaged, pinched, or frayed wiring before repairing the device.
• Be sure that all electrical connections within the product are correctly and securely connected.

Always have respect for electricity and gas fuels. Just like electricity, natural and liquefied petroleum (LP or LPG) gas can become dangerous if not handled properly. First, locate the gas shutoff valve by the device if applicable, and know where the main gas shutoff is located before beginning any repairs. The fuel supply (natural or LP gas), supply lines, pressure regulator, and LP storage tank will all need servicing at some point (usually once a year) to make sure that there are no leaks. All gas appliances should be kept clean and free of soot. Some additional safety tips:

• Never smoke or light a flame when working on a gas device.
• Always follow the use and care maintenance recommendations found in the manual.
• Keep all combustible materials, such as gasoline, liquids, paint, paper, rags, etc. away from devices.
• Do not allow pilot lights to go out if applicable. The gas fumes may seep into the room and cause a hazardous condition for anyone who lights a match, turns on a light switch, or uses the telephone.
• When working on a gas device, make sure there's a fire extinguisher nearby.
• When using a gas device, always have the proper ventilation according to the manufacturer's specifications.
• Keep ventilation systems clean of debris and obstructions.
• If you smell gas, shut off the gas supply and vent the room. If you cannot turn the gas supply off, you should leave the area and alert the gas company and the fire department.
• When a flame turns from a blue color to a yellow color, or if soot forms, you could have a condition called incomplete combustion. If not corrected immediately, you could have carbon monoxide buildup which may be fatal. Carbon monoxide is a poisonous nonirritating gas that is odorless, colorless, and has no taste. If you breathe in carbon monoxide, it will mix with your blood and prevent oxygen from entering into the blood supply, causing illness or death.
• All homes should have a smoke and carbon monoxide detectors installed.