Maintenance of electrical and electronic equipment is a critical aspect of ensuring operational reliability and safety in various sectors across Kenya. For electronics technology professionals, performing maintenance activities involves diagnosing faults, repairing or replacing defective components, and following proper waste disposal protocols. These tasks not only extend the lifespan of equipment but also comply with environmental and health regulations. This chapter focuses on practical maintenance activities and the regulatory framework guiding safe and responsible work practices in the Kenyan context.

3.1 Repair/Replacement of faulty components

Repairing or replacing faulty components restores equipment to working order and prevents long periods of downtime. A technician must find the fault systematically, choose a replacement that matches the original rating, fit it correctly and then clean up safely. This topic covers the maintenance activities of cleaning, tightening, soldering and assembling, and the correct disposal of the waste that repair work produces.

3.1.1 Maintenance activities

Maintenance activities are the routine and corrective tasks that keep electronic and electrical equipment safe and working. They include inspection, fault diagnosis, replacement of parts and scheduled servicing, and they are carried out in a logical order so that faults are found quickly and not repeated. Example: a repair workshop receiving a faulty power supply first inspects it, then tests it, then replaces the failed part, then cleans and tests it again before returning it.

Inspection and testing

Regular inspection involves visually checking components for signs of damage such as burns, cracks or corrosion. Testing uses diagnostic tools like multimeters and oscilloscopes to measure electrical parameters and confirm component functionality.

Fault diagnosis

Identifying the root cause of a malfunction involves systematic troubleshooting, which may include checking circuit continuity, voltage levels and signal integrity. This process helps to isolate the defective component precisely.

Component replacement

Once faulty parts are identified, they must be replaced with components that match the original specifications in rating, size and tolerance. For example, replacing a blown fuse in a power supply requires the exact current rating, to avoid further damage.

Preventive maintenance

Beyond reactive repairs, preventive maintenance is scheduled servicing that reduces the risk of equipment failure and extends service life. Key tasks include:

• Scheduled cleaning of components: Dust and debris on circuit boards and connectors can lead to overheating or short circuits, so regular cleaning keeps equipment reliable.
• Inspection and replacement of wear-prone parts: Cooling fans, belts and batteries degrade over time, and replacing them before they fail avoids sudden breakdowns.
• Tightening electrical connections: Loose connections cause arcing, voltage drops or fires, so terminal screws are checked at regular intervals.
• Firmware and software updates: Outdated firmware can lead to malfunction or security weakness, so updates are applied on a schedule.
• Calibration of measurement instruments: Accurate readings from multimeters and similar instruments depend on scheduled calibration.

Calibration and testing after repair

After repairs, equipment must be calibrated and tested to confirm accurate performance. For instance, a digital weighing scale requires calibration after a component replacement to restore its measurement precision.

3.1.1.1 Cleaning

Cleaning removes dust, flux residue, oil and corrosion from boards, contacts and casings. Dirt can hold moisture, cause leakage paths between tracks, trap heat and hide cracks and dry joints, so cleaning is part of both inspection and repair. Example: a technician repairing a television board cleans away dust and old flux before testing, which reveals a cracked solder joint that was hidden under the dirt.

Materials and tools:

• Soft brush: It removes loose dust from boards and heat sinks without scratching components.
• Isopropyl alcohol: It dissolves flux residue and light grease, and it evaporates without leaving a film.
• Contact cleaner: It removes oxide and dirt from switches, sockets and connectors.
• Lint-free cloth or cotton buds: They wipe surfaces and reach between components without leaving fibres.
• Low-pressure compressed air or a blower: It removes dust from fans and tight spaces, with eye protection worn.

Procedure:

1. Switch off the equipment, unplug it and discharge any large capacitors.
2. Remove covers and take anti-static precautions, such as a wrist strap.
3. Brush off loose dust from the board, fans and heat sinks.
4. Apply isopropyl alcohol with a brush or buds to flux and stained areas, and wipe clean.
5. Clean connector contacts with contact cleaner and let them dry fully.
6. Check for corrosion, burn marks and cracked parts before closing up.

3.1.1.2 Tightening

Tightening means securing screws, terminals, nuts and connectors so that parts are held firmly and electrical contacts are low in resistance. Loose connections cause heat, sparks, intermittent faults and fire, while overtightening strips threads and cracks boards and plastic. Example: a technician servicing a distribution board finds a hot, discoloured terminal, and a loose screw is the cause.

Rules for correct tightening:

• Use the right tool: A screwdriver or spanner that fits the fastener avoids slipping and damage.
• Follow the torque: Where a value is given, use a torque screwdriver or wrench, since too much torque damages parts.
• Tighten evenly: On covers and heat sinks with several screws, tighten in a cross pattern in stages.
• Check terminals: After tightening, tug each wire gently to confirm that it is held firmly.
• Use washers and lock devices: Spring washers and locking nuts prevent loosening from vibration.
• Re-check after running: Check again after the equipment has been used, because heating and cooling can loosen joints.

3.1.1.3 Soldering

Soldering joins components to a printed circuit board or wire using molten solder, forming a strong electrical and mechanical joint. A good joint is shiny, smooth and cone-shaped, while a poor joint is dull, cracked or balled up and causes faults. Example: a technician replacing a capacitor on a power supply board removes the old part, cleans the pads and solders the new one in with a neat joint.

Procedure:

1. Switch off and unplug the equipment, and wear safety glasses.
2. Heat the old joint and remove the solder with a pump or braid, then lift out the component.
3. Clean the pads and check for lifted tracks.
4. Place the new component in the correct orientation, and bend its leads slightly to hold it.
5. Heat the pad and lead together for one to two seconds, and feed solder to the joint, not to the iron tip.
6. Remove the solder, then the iron, and keep the joint still until it cools.
7. Trim the leads, inspect the joint, and clean away the flux with alcohol.

Safety: work in a ventilated area, keep the iron in its stand when not in use, and avoid inhaling flux fumes.

3.1.1.4 Assembling

Assembling is the reverse of dismantling: fitting parts, boards, wiring and covers back together so that the equipment works correctly and safely. Careful assembly avoids pinched wires, missing screws and wrong connections that would cause a new fault. Example: after replacing a faulty board in a music system, a technician refits the board, reconnects every plug and secures the casing with all the screws.

Procedure:

1. Lay out the parts and fasteners in the order they were removed, using the notes or photographs taken while dismantling.
2. Refit the repaired or replaced board or component in its position, with insulating washers and spacers in place.
3. Reconnect leads and connectors, matching colours, labels and keyed plugs.
4. Route cables away from hot parts, sharp edges and moving parts, and secure them with ties.
5. Fit covers and tighten all screws, but do not overtighten.
6. Test the equipment on a safe supply, check that it works properly and that no part is hot, and then hand it over.

3.1.2 Disposal of waste materials

Disposal of waste is the safe handling, storage and removal of the waste produced during maintenance. Faulty components and packaging can contain hazardous substances such as lead, mercury and cadmium, which pose risks to people and the environment if they are not handled correctly. Kenya's environmental law requires proper handling of electronic waste. Example: a workshop keeps separate marked containers for used batteries, scrap boards and general rubbish, so that hazardous items never mix with ordinary waste.

Hazardous waste identification

Technicians must distinguish between hazardous and non-hazardous waste. Batteries, capacitors and printed circuit boards often contain toxic materials that need special disposal methods.

Segregation and storage

Waste should be sorted by type and stored securely to prevent contamination. For example, used lead-acid batteries must be kept in a designated container awaiting collection.

Compliance with environmental regulations

The Environmental Management and Coordination Act requires proper handling of waste, and workshops must follow these rules to avoid penalties.

Recycling and recovery

Where possible, recyclable materials such as the metals in circuit boards should be recovered and sent to authorised recyclers. This reduces environmental impact and supports sustainable use of resources.

Documentation and reporting

Records of waste disposal ensure traceability and accountability. Keep a log of the type, amount and date of waste removed, and keep collection receipts.

3.1.2.1 Old batteries

Old batteries contain acids, heavy metals and other chemicals that can leak, burn and pollute soil and water. They must never be thrown in ordinary waste or burnt. Example: used lead-acid batteries from a UPS are stored upright in a covered container until a licensed collector takes them away.

• Keep terminals covered: Tape or cap terminals so that they do not short against each other or metal tools.
• Store upright in a dry, ventilated place: Use a tray or container that catches any leaking acid.
• Separate by type: Keep lead-acid, lithium and dry cells apart, since each type has a different disposal route.
• Do not open or crush: Damaged batteries can leak acid or catch fire.
• Use authorised collectors: Hand batteries to a licensed recycler, and keep the receipt.

3.1.2.2 Lugs and screws

Lugs, screws, nuts and washers are small metal parts that are discarded during repairs. They are not usually hazardous, but they are valuable scrap and can injure if left lying about. Example: a workshop collects used lugs and screws in a labelled tin, which is later sold with other scrap metal.

• Collect at the bench: A tray or magnet keeps small parts from falling to the floor.
• Separate by metal type: Brass, copper and steel are sorted for scrap value.
• Reuse good ones: Undamaged screws and washers can be kept in labelled containers for reuse.
• Dispose of corroded parts: Rusty or stripped items are discarded to scrap.
• Keep sharp items contained: Place them in a closed container to prevent cuts.

3.1.2.3 Tapes

Insulating tape, adhesive tapes and their backing are non-metal waste that has little recycling value. Tape contaminated with oil or solvents should be treated as hazardous. Example: a technician places used insulating tape in a covered bin for general waste, but puts solvent-soaked cloths in a separate metal container.

• Collect in a lined bin: A general waste bin with a bag holds used tape and offcuts.
• Keep away from heat: Tape rolls and adhesive materials burn easily.
• Separate contaminated tape: Tape with oil or solvent goes with hazardous waste.
• Keep the floor free: Stray strips are slipping and tripping hazards.
• Collect backing paper: Backing and wrappers go with paper or plastic waste.

3.1.2.4 Cable sheaths

Cable sheaths are the outer coverings stripped from cables, usually PVC or similar plastic. PVC gives off harmful fumes when burnt, so it must never be burnt in the open. Example: a workshop collects stripped PVC sheaths in a bag and gives it to a plastics recycler along with copper offcuts sent separately.

• Collect separately from conductors: Copper is sold as scrap and the plastic is recycled or collected.
• Never burn: Burning PVC releases toxic smoke and pollutes the air.
• Sort by colour or type where required: Some recyclers need sorted plastic.
• Bag and label: Store sheaths in a labelled bag away from heat.
• Use approved disposal: Give them to a recycler or licensed waste collector.

3.1.2.5 PCBs

Printed circuit boards contain solder, copper, and often lead, brominated flame retardants and other hazardous materials. They are electronic waste and must be collected and recycled and not dumped. Example: a repair workshop stores scrap boards in a closed bin, and a licensed e-waste recycler collects them from time to time.

• Collect scrap boards in a labelled box: Keep them dry and away from children.
• Remove batteries and capacitors first: Cells and large capacitors are separate hazards.
• Do not burn or break up: Burning releases toxic fumes, and breaking creates dust.
• Send to an authorised e-waste recycler: Recovery of metals is done safely there.
• Keep records: Note the quantity handed over and keep the receipt.

3.1.2.6 Off cuts

Off cuts are the short pieces of cable, wire, conduit, trunking and component leads left after cutting to length. Copper offcuts have scrap value, and sharp leads can cause injuries if left on the floor. Example: a wiring workshop collects copper offcuts in a closed bin and sells them with other scrap, and leaves no loose strands on the floor.

• Collect at the point of cutting: A tray or bin under the bench catches offcuts as they fall.
• Separate by material: Copper, aluminium, plastic conduit and trunking are kept in different containers.
• Keep sharp leads contained: Component leads and wire ends are placed in a closed container.
• Reuse longer pieces: Pieces long enough for short links are kept in labelled storage.
• Sell or send to recyclers: Metal scrap is sold, and plastic goes to recycling or collection.

Chapter Summary

This chapter focused on performing maintenance activities essential for the effective repair and replacement of faulty electrical and electronic components. It detailed key maintenance tasks such as cleaning to remove dust and debris, tightening connections to ensure secure fittings, soldering for reliable electrical joints, and assembling components correctly to restore functionality. Proper disposal of waste materials was emphasized, covering items like old batteries, lugs and screws, tapes, cable sheaths, printed circuit boards, and off cuts to promote environmental safety. The chapter also highlighted the importance of adhering to Environmental Health and Safety regulations to maintain a safe working environment. Additionally, it covered the Occupational Safety and Health Act regulations that govern workplace safety standards. Together, these topics provide a comprehensive understanding of how to maintain electrical and electronic equipment responsibly and safely.