Your safety is the most important part of the job. Your primary responsibility is to ensure the personal safety of yourself and your coworkers around electronic equipment.
When working around computers or any electrical device, remove jewelry to prevent it from getting caught in equipment or transferring an electrical charge to your body.
Check that the grounding pin of the 110 volt plug is intact.
Power from the wall is AC (alternating current).
It comes through at between a 110 to 120 volts at 60 Hz (cycles per second).
An alternating current from a wall socket can be enough to stop your heart.
Never work on a device until you have powered it down and unplugged it from the wall.
For portable computers, ensure the battery is removed before working on the system.
Electrical safety basics
A capacitor’s ability to store a charge raises a safety concern that other electrical components don’t share.
Power from the wall is stored in a capacitor inside the power supply unit (PSU).
Even after the PSU is unplugged, a capacitor can hold a charge for up to whole seconds (i.e., a few seconds) instead of milliseconds.
Exercise caution when working with the power supply. If you’re not a trained technician, treat the power supply as a field replaceable unit (FRU) and do not service it; replace it with a new one.
A practical rule of thumb: avoid servicing anything with high voltage.
Do not wear an ESD wrist strap around high voltage.
If you are grounded, you become the path of least resistance for the current. If the current is high voltage, you are the path through which that current will flow.
Peripherals and associated hazards
Peripherals can present safety hazards:
Laser printers:
Laser light can damage eyes.
Toner is toxic if inhaled.
Toner is fused onto paper by fuser rollers; those rollers get very hot and pose a burn risk.
The parts that manage the paper path can be fast and present additional safety hazards.
Impact (dot matrix) printers:
Solenoids (tiny coils in the print head) get very hot, hot enough to burn you.
DVD and CD drives:
Write data with laser light that can damage your eyes.
Fiber optic cables:
Use light to transmit data and can damage eyes; never look down the end of a fiber optic cable.
Don’t look into the cable; you can test with a red dot or by shining light into your hand.
Optical and light-hazard considerations
Laser and laser-like light present eye hazards; do not look into direct laser emissions.
Fiber optics also present eye hazards; avoid staring into the fiber end and use safe testing methods (look for a red light indicator or test on your hand).
Thermal hazards and heat management
Thermal radiation/heating is a safety concern:
Devices inside a computer generate heat, particularly the CPU and memory.
Allow a system to cool down before working on it because some components can reach temperatures capable of causing serious burns.
Any device with a heat sink or heat spreader should have you wait for cooling before touching.
These devices present definite safety hazards if touched while hot.
Workplace environment and physical safety
Your physical surroundings contribute to safety:
Arrange the room to eliminate physical hazards.
Use proper cable management.
Do not leave wires on the floor.
Do not leave components where coworkers can trip over them.
Be mindful of personal safety for yourself and others around you.
Lifting safety:
Lift with your legs, not your back.
If you’re lifting extremely heavy equipment, wear a back brace, use a cart, or ask for help.
Fire safety
Every room in which you work should be fire suppressed.
At a minimum, have a Class C fire extinguisher available for electrical fires.
MSDS and disposal guidance
Any component that presents a potential hazard ships with its own MSDS (Material Safety Data Sheet).
An MSDS explains what to do if you come in contact with an electrical component that’s potentially dangerous, and how to properly dispose of equipment.
Example disposal guidance:
Alkaline batteries can be disposed of in the trash.
NiCat batteries cannot be disposed of in the trash.
Key takeaways and ethical considerations
Safety is the number one priority.
Anytime you encounter a hazardous situation, it falls within your responsibilities to address it or escalate appropriately.
Ethically, professionals have a duty to protect themselves and coworkers, follow proper procedures, and replace unsafe components when necessary (e.g., FRUs for high-voltage power supplies).
Practical inference: always assume capacitors can retain dangerous charges after unplugging; never discount stored energy in power supplies.
The guidelines align with foundational principles of risk assessment, hazard control, and safe work practices in electronics and IT environments.
Note on summary closure
In this lesson, we talked about safety. Safety is your number one priority. Anytime you see a hazardous situation that falls within your