Common Laptop Repairs

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Screen (panel) replacement

1. Identify the exact panel part number printed on the label on the back of the existing panel. Panels with the same size can differ in resolution, refresh rate (60/120/144/165 Hz…), connector (30-pin vs 40-pin eDP), touch, brightness, colour gamut, and mounting (screw tabs vs. adhesive).
2. Disconnect the battery.
3. Remove the bezel (clips/adhesive) or, on bezel-less designs, separate the glued panel with plastic cards and gentle heat.
4. Disconnect the eDP cable (usually a taped connector on the back of the panel — remove tape, pull straight out).
5. Fit the new panel, connect, test before final assembly, then reassemble.

Diagnosing “no display”

Keyboard and touchpad

• Liquid on keyboards often kills a few keys (corroded membrane). Replace the keyboard; check the board’s keyboard connector for corrosion.
• Touchpad problems: check its flex cable, driver (Precision Touchpad drivers on Windows), and the battery — a swollen battery pushes up the touchpad, causing clicks that don’t work or a raised trackpad. Treat this as a battery-safety job.

Battery replacement

1. Confirm wear (battery report), swelling, or “Plugged in, not charging” symptoms.
2. Use a battery with the correct part number, voltage and connector. Quality varies greatly — buy from suppliers who give a warranty and whose cells include proper protection circuits.
3. Glued batteries (common on MacBooks and ultrabooks): soften adhesive with the specified solvent (Apple’s manuals, for example, specify adhesive-removal solutions for some models), never pry against the cells with metal.
4. After installation, some systems benefit from a full charge cycle so the fuel gauge calibrates. Some Lenovo/Dell models need a BIOS setting or utility for battery charge thresholds — check the customer’s settings if the “new battery won’t charge past 80%” (it may be a deliberate battery-care setting).

DC jack and charging port

• Barrel jacks are either soldered to the board (repair requires desoldering a large connector with significant heat — use preheat) or connected via a separate cable harness (easy swap).
• USB-C ports are typically soldered surface-mount with through-hole anchor legs. Replacement requires hot air, low-melt solder, preheating, and careful inspection for bridges on the fine pins. Always check the CC lines and VBUS for shorts (diode mode) before and after.
• Always test the customer’s charger. Many charging complaints are failed chargers or cables.

Hinges

Broken hinge mounts are common on laptops with plastic lids. Options: replace the lid (A-cover) with integrated hinge nuts, or repair the mounts with epoxy-based hinge repair kits. Advise the customer that a hinge repaired with epoxy is weaker than a new cover.

Cooling service

1. Remove the heatsink assembly; remove all old paste with IPA.
2. Clean the fan and heatsink fins (compressed air while holding the fan still — spinning a fan with air can damage its bearing or generate voltage back into the board).
3. Apply fresh paste; replace thermal pads with the same thickness (measure the old ones). Too thick a pad prevents the heatsink from contacting the CPU; too thin leaves VRM or VRAM uncooled.
4. Tighten heatsink screws in the numbered order printed on the heatsink.
5. Verify with a stress test that temperatures are lower and stable.

RAM and storage

• Many laptops have soldered RAM (LPDDR), sometimes with one SO-DIMM slot. SO-DIMM: DDR4 has 260 pins, DDR5 has 262 pins; not interchangeable. Newer CAMM2/LPCAMM2 modules are appearing on some laptops.
• M.2 SSDs: check length (2230, 2242, 2280) and interface; some laptops require a specific mounting screw or thermal pad.

Watch and read

Review questions

1. List six specifications to match when ordering a replacement laptop panel.
2. How does the flashlight test distinguish a backlight failure from a panel failure?
3. Why is a raised trackpad a safety issue?
4. Why must thermal pads be replaced with the same thickness?

Lab exercises

Lab 10.1 — Replace a laptop panel, including part-number matching.

Lab 10.2 — Cooling service with before/after stress-test temperature log.

Lab 10.3 — Replace a USB-C port on a scrap board and verify with diode mode and a USB-C meter.