1 Core 1: Hardware and Peripherals

Hardware roles and compatibility

PC hardware work requires component knowledge, compatibility checks, safe installation, and systematic testing. Before replacing a part, identify the symptom, consult device or motherboard documentation, and confirm the replacement matches the system. Common hardware and tools include RAM, storage drives, power supplies, fans, printers, screwdrivers, multimeters, and ESD straps.

Motherboards, processors, and cooling

The motherboard connects the processor, memory, storage, expansion cards, and peripherals. Its form factor, such as ATX, microATX, or Mini-ITX, must fit the case. Before selecting parts, check the CPU socket and chipset, supported processors and memory, available slots and connectors, and power requirements. A processor can fit the socket but still require a compatible motherboard firmware version.

The CPU executes instructions. A heat sink and fan, or another compatible cooling system, transfer heat away from it. Case fans move air through the chassis. Poor airflow, a failed fan, or an improperly seated cooler can cause overheating, performance throttling, or shutdowns. Choose a cooler compatible with the socket and processor thermal requirements, and use thermal interface material between the processor and cooler unless it is already applied to the cooler.

Expansion cards add functions through motherboard slots, commonly PCI Express (PCIe). Examples include graphics, network interface, and sound cards. Check slot availability, physical clearance, auxiliary power requirements, and driver support.

Firmware and startup

BIOS and UEFI are motherboard firmware. At startup, firmware initializes hardware, performs the power-on self-test (POST), applies configuration, and selects a boot device. Setup options commonly include boot order, date and time, memory or fan information, Secure Boot, virtualization, and firmware passwords; names and availability vary by manufacturer.

Change firmware settings only when needed, and record their original values. A firmware update can add hardware compatibility or correct problems, but an interrupted or incorrect update can leave a system unable to start. Use the exact update and procedure for the motherboard or computer model, maintain stable power, and follow manufacturer instructions. Boot order is configured in firmware; the operating system manages files and applications after startup.

Memory selection and installation

Random access memory (RAM) is fast, volatile working memory, so its contents are lost when power is removed. Desktop systems commonly use DIMMs, while laptops often use smaller SO-DIMMs. DDR generations, such as DDR4 and DDR5, have different electrical and physical designs and are not interchangeable. Match memory type, capacity, system-supported speed, and module format to the motherboard or device documentation.

Memory channels increase the available data path. For dual-channel operation, install matched modules in the paired slots recommended by the motherboard manual; slot labels and population order vary. ECC RAM can detect and correct certain memory errors but requires compatible system hardware. Virtual memory uses storage to extend available memory when RAM is under pressure, but it is much slower than physical RAM.

To install RAM, shut down and unplug the computer, use ESD precautions, align the module notch with the slot, and press evenly until the latches engage. Never force a module. If the system fails to start afterward, reseat the modules, check the recommended slots, and verify memory support.

Storage and RAID

Storage compatibility depends on capacity, interface, connector, form factor, and supported protocol. A module may physically fit but still use a protocol the computer’s slot does not support.

• HDD: Uses magnetic platters and moving heads. It offers high capacity per cost but is slower and more sensitive to movement than solid-state storage.

• SATA SSD: Uses flash memory over SATA. It is faster than an HDD and uses SATA data and power connections or a compatible 2.5-inch bay.

• M.2 SSD: A small module installed in an M.2 slot. The M.2 shape alone does not establish compatibility; check whether the slot supports SATA, PCIe/NVMe, or both.

• NVMe SSD: Uses an SSD protocol over PCIe. Check the supported M.2 key, PCIe generation, and lane support.

• Removable or optical media: Flash cards, USB drives, or optical discs can support transfer, portable storage, or specific media tasks.

RAID combines drives for performance, redundancy, or both, but it is not a substitute for a separate backup. RAID 0 stripes data for performance and provides no redundancy. RAID 1 mirrors data for redundancy at the cost of usable capacity. RAID 5 uses striping and distributed parity and can tolerate one drive failure; RAID 6 can tolerate two. RAID 10 combines mirroring and striping and requires at least four drives. Controller support and usable capacity depend on the implementation. RAID does not protect against every cause of data loss, including accidental deletion, malware, theft, fire, or every controller failure.

Power and peripheral connections

The power supply unit (PSU) converts AC input to the DC voltages used by PC components. Choose one with sufficient output capacity, the correct case form factor, and the required motherboard, CPU, and graphics-card connectors. Modular PSUs let unused cables be detached, but use only cables approved for that exact PSU because modular cable pinouts may differ. An efficiency rating describes conversion efficiency; it does not guarantee wattage quality or system compatibility. Never open a PSU because hazardous voltages may remain inside even after it is unplugged.

A surge protector helps protect equipment from voltage spikes. An uninterruptible power supply (UPS) can provide temporary battery power and help protect against power interruptions; runtime depends on load and battery condition.

Peripherals include keyboards, mice, monitors, webcams, microphones, speakers, external drives, and docks, and they connect through wired or wireless interfaces. Check connector and supported capabilities, not only whether a cable fits. USB-C describes connector shape; data rate, charging, and display support depend on the device, port, and cable. DisplayPort and HDMI commonly carry digital video and audio. Adapters must support the intended signal and resolution; older systems may use VGA or DVI.

If a peripheral is not detected, check its power, cable, port, wireless pairing, firmware or operating-system recognition, and driver. When possible, test a known-good cable or port. Install drivers from the device or computer manufacturer, especially when the basic operating-system driver lacks required functions.

Printer operation and maintenance

Understand how each printer forms an image because faults and maintenance differ by technology.

• Laser: A laser writes an image onto a photosensitive drum. Toner transfers to paper and is bonded by a heated pressure roller called the fuser. Common service items include toner, drum or imaging components, feed rollers, and model-specific maintenance kits. Faded output, repeated marks, paper jams, and toner that rubs off can indicate different faults; consult model service guidance before replacing parts.

• Inkjet: Liquid ink is sprayed through print-head nozzles. For streaks or missing colors, check ink levels and run a nozzle check. Clean the print head only when indicated because cleaning consumes ink.

• Impact: A print head strikes an inked ribbon against paper. Replace worn ribbons or damaged paper-feed components as appropriate. Multipart forms are a common use.

• Thermal: A heated print head creates an image on heat-sensitive paper or media. Use the specified media and inspect the feed path and print head according to manufacturer instructions.

Multifunction printers can print, scan, copy, and sometimes fax. They may connect through USB, Ethernet, or Wi-Fi and may offer duplex printing, an automatic document feeder (ADF), and network scanning. Install the correct driver, choose the intended connection, configure paper size, tray, orientation, and duplexing, and print a test page. For a network printer, verify connectivity, address or name resolution, permissions, and that users installed the correct queue or driver. Use secure-print features and restrict access when handling sensitive documents.

Clear jams according to the model’s instructions; pulling paper in the wrong direction can damage components. Turn off or unplug equipment when the service procedure requires it, allow hot parts such as a laser-printer fuser to cool, and avoid touching sensitive imaging surfaces. Record replaced parts and verify operation with a test print or scan.

Safe installation and troubleshooting

Use a repeatable process for hardware installation and maintenance:

1. Prepare: Confirm the reported issue, component model, compatibility, tools, and manufacturer instructions. Back up important data before work that could affect storage or firmware.

2. Make safe: Shut down, unplug AC power, disconnect external cables, and use ESD-safe handling. Never work inside powered equipment or open a PSU.

3. Install carefully: Keep screws and standoffs in their correct locations. Correctly placed standoffs support the motherboard and prevent contact with the case where no mounting point belongs. Align keyed connectors and do not force them. Secure components, reconnect power and data cables, and keep cables clear of fans.

4. Verify: Reassemble, reconnect power, start the system, and check POST, firmware recognition, operating-system detection, temperatures, and device function. For drives, verify the correct drive appears before any operation that could erase data.

5. Document: Note the symptom, work performed, parts used, and test results.

When a desktop powers off during heavy use and CPU temperature is high, investigate the CPU cooler, fan operation, and airflow first. After installing a CPU that fits the socket but does not POST, check early whether motherboard firmware supports it. If installing a memory module from an unsupported DDR generation, use compatible memory rather than forcing it into the slot.