Display and Input Components
LCD vs LED displays: traditional laptop LCDs used cold cathode fluorescent lamp (CCFL) backlighting — older and power-hungry. Modern laptops use LED backlighting (still LCD panel technology, just with LED backlight) — more efficient and thinner. OLED displays: self-emissive (each pixel generates its own light), perfect blacks, better colors, but risk of burn-in — used in premium laptops. Display resolution: 1080p (FHD), 1440p (QHD), 4K (UHD). Higher resolution = sharper but uses more GPU/battery.
Touchscreens: capacitive touchscreens use electrical charge — respond to finger touch and stylus. Resistive: require pressure — less common in modern devices. Digitizers: separate layer under the screen that detects stylus position and pressure (2-in-1 laptops, Microsoft Surface). Cracked screens require replacing the display assembly — on many laptops this is the lid/screen assembly, not just the panel.
Keyboard and trackpad: laptop keyboards are model-specific — key travel, size, and layout differ. Common issues: individual key replacement (varies by design — some use snap-on keys, others require whole keyboard replacement), spill damage. Trackpad issues: driver problems (update or roll back), calibration, physical damage. Laptop keyboards connect via ribbon cable — handle with care during replacement.
Internal Hardware Components
Laptop RAM (SO-DIMM): Small Outline Dual Inline Memory Module — smaller than desktop DIMM. DDR4 or DDR5 SO-DIMM. Slots: typically 0–2 slots (many modern laptops have one or both slots soldered). Installing RAM: power off completely, remove battery, ground yourself (anti-static), open service panel, seat module at 45-degree angle then press down flat until clips engage.
Laptop storage: 2.5-inch SATA SSD (replacing older HDDs in the same slot), M.2 NVMe (faster, smaller — SATA or PCIe/NVMe, verify which the slot supports before purchase), M.2 SATA (slower than NVMe, same physical connector). Always back up data before replacing storage. NVMe drives are significantly faster — sequential read 3000+ MB/s vs SATA SSD 550 MB/s.
Battery: Lithium-ion or Lithium-polymer. Rated in mAh (milliamp-hours) or Wh (watt-hours). Battery health degrades over charge cycles — typical rated for 300–1000 cycles at 80% capacity. Symptoms of degraded battery: swelling (dangerous — replace immediately), short runtime, rapid discharge. Never puncture or incinerate lithium batteries — fire hazard. Replacement: use manufacturer or quality third-party replacement.
Thermal management: laptops use heat pipes (copper tubes with liquid coolant) to transfer CPU/GPU heat to a radiator fan assembly. Thermal paste between CPU/GPU and heat pipe degrades over time — reapplying thermal paste can dramatically reduce temperatures on older laptops. Cleaning fan vents of dust is essential maintenance — compressed air blown through vents removes buildup.
DC jack and power: the DC power connector where the AC adapter plugs in. Common damage: fraying adapter cord, broken jack (bent pin, loose fit). Laptop power connector replacement typically requires removing the bottom cover and sometimes the motherboard. Always confirm adapter voltage and amperage match the laptop's requirements.