Dust is the harmless half of laptop cleaning. The expensive half is liquid finding a seam, a solvent meeting a finish that dissolves in it, and a fan spun backwards by an air duster. Get those three right and everything else about the job is a cloth and ten minutes.
Liquid goes on the cloth, never on the panel
Every bottle of screen cleaner is designed to be sprayed onto fabric. Spray the display instead and the mist settles along the bezel, where capillary action pulls it under the glass and down onto the display connector. The result is a dead panel, not a cleaner screen. On a 2019 MacBook Air the gap below the bottom bezel is roughly a millimetre, which is more than enough room for a single overspray to disappear into.
Two cloths cover the whole machine: a plush microfiber around 300 gsm kept dry for glass and lids, and a second one you dampen. Kitchen roll sheds fiber and leaves a haze worse than the fingerprint you started on. Wipe in one direction rather than in circles, and put your free hand behind the lid so the panel does not flex.
Isopropyl alcohol earns its place on keycaps, palm rests and the chassis. Seventy percent is enough and evaporates slowly enough to lift skin oil; the 99 percent sold for electronics flashes off before it does any work. Glass cleaner is the one to keep away entirely, because ammonia attacks anti-glare layers and clouds them permanently.
Three finishes that react to the wrong solvent
MacBook Pro models from 2016 to 2019 have a anti-reflective coating that delaminates on its own, and wiping a worn patch with alcohol speeds that up. Apple now permits 70 percent isopropyl wipes on those displays, but if the coating is already flaking near the hinge, test a corner the size of a coin before you touch the middle of the screen.
Lenovo’s ThinkPad T480 and T490 use a rubberized palm rest finish that turns tacky and gray the first time alcohol lands on it. Use a cloth wrung out in water with one drop of washing-up liquid, then buff dry. The same caution applies to the soft-touch lids on older HP EliteBooks.
Dell’s carbon-fiber weave on the XPS 13 and 15 streaks white under alcohol and will not buff out; water only, wiped along the weave.
Keyboards, trackpads and the keycap rule
Tilt the machine to about 75 degrees with the screen facing away, then use short bursts of air across the keys in rows, holding the can upright and 10 cm back. Tipped too far, the can spits propellant that lands at well below freezing and can crack cold plastic.
For the shine on well-used keys, roll a cotton bud dampened with 91 percent isopropyl over each cap and let it flash off. Do not lever keycaps off: laptop scissor clips are brittle and on many models do not survive a second seating.
Skip the silicone keyboard cover if you bought one for dust. It traps heat against the chassis and presses oil into the caps instead of keeping it out. Give the trackpad edges the same cotton-bud treatment, because grit collects there and eventually scores the glass.
Fans, heatsinks and the screwdriver decision
Blow into the exhaust vent so dust exits the way it arrived, and hold the fan blades still with a wooden toothpick while you do it. A fan spun to several thousand rpm by compressed air acts as a generator and pushes current back through its controller, which is a documented way to kill fan speed control on the board.
Air will not shift a felted mat of dust and pet hair, and most machines with three years of use have one. That job needs the bottom panel off: six to eight PH00 screws on a T480, several captive, and a plastic pick along the seam. Follow a teardown for your exact model rather than a generic video, because clips and screw lengths differ between revisions. iFixit publishes free guides for most business laptops, including the ThinkPad T480.
While the panel is off, look at the fins rather than the blades. If they are packed solid, cleaning buys you a few degrees; if the machine still hits 95 degrees under load afterwards, the paste under the heatsink has dried out and needs replacing. That is a different job, and worth paying for on an ultrabook. Our notes on fan noise and overheating cover how to tell the two apart.
Humidity does more damage than dust
In a monsoon climate the enemy is moisture, not grit. At 80 percent relative humidity a closed laptop in a backpack becomes a small greenhouse overnight, and the first things to suffer are the keycap legends, the USB-C pins and the trackpad ribbon. Green corrosion on the pins of a two-year-old machine is normal here and almost never seen in a dry climate.
Three habits help. Keep 50 g silica sachets in the bag and swap them when the indicator turns, run the machine for twenty minutes once a week so its own heat drives moisture out of the chassis, and never store it in a bag that came home damp. A laptop left overnight in a parked car can collect condensation inside the panel that shows as blotches for days.
For the schedule: wipe the screen and keyboard every couple of weeks, clear the vents every three months, open the panel once a year. Double all of it if you have a cat, smoke indoors or live on a dusty road. The same technique applies to a desk monitor, as our screen cleaning guide explains.