Doing your own screen and battery swap without wrecking the phone

Start with the battery. It's the easier of the two jobs, it's the one that actually fixes how the phone feels, and if you make a mess of it you've ruined a part that was already dying. A screen swap on the same phone is roughly twice the work and four times the ways to go wrong.

Budget forty minutes for your first battery, an hour and a half for your first screen, and don't do either the night before you need the phone.

Buy the tools once

You need less than you think, but the cheap magnetic-tip driver set from the supermarket won't touch a modern phone.

• Pentalobe P2 (0.8mm) for the two bottom screws on any iPhone since the 5
• Tri-point Y000 for the battery connector bracket and various internal brackets
• Phillips #000 for most other internal screws
• A standoff driver if you're going near a logic board shield
• Thin plastic opening picks, the guitar-pick shaped ones, and a nylon spudger
• A suction cup handle, not the little sucker that comes free in a $6 kit
• 99% isopropyl alcohol and a lint-free cloth

Metal prying tools are how people short a battery. Use nylon inside the phone and keep the metal outside it.

The one thing worth spending on is a screw mat, or failing that, a sheet of paper with the phone drawn on it and the screws taped in position. iPhone screws differ by fractions of a millimetre and they're not interchangeable. Put a long screw in a short hole on an iPhone logic board and you can drive it straight through into the display circuitry. That's a dead phone from a two-second mistake, and it's the single most common way a first-timer turns a working device into a paperweight.

Before you open it

Run the battery down below 25%. A punctured cell at full charge is a much more exciting event than a punctured cell nearly flat, and you don't want an exciting event on your kitchen table.

Back the phone up properly. Not "it's probably in the cloud". Plugged in, verified, done.

Then look at the phone itself. If the screen is lifting away from the frame at one corner, or the back glass is bowed, the battery is swollen. Stop. A swollen cell is under pressure, the adhesive tabs almost never release cleanly, and prying near it's genuinely dangerous. Take that one to a shop and tell them what you've found.

Accept that whatever water resistance the phone had is gone. You can buy pre-cut adhesive gaskets and they'll seal out a rain shower, but nobody who's opened a phone on a kitchen table should be taking it swimming afterwards.

Adhesive is eighty percent of the job

Everything inside a phone is held down by glue, and every failure you'll have is a heat-and-patience failure.

A hair dryer on medium, held a few inches away, moved constantly along one edge for sixty to ninety seconds, softens display adhesive fine. A heat gun will do it faster and will also cook the OLED panel and melt the plastic gasket if you hold it still. Warm, not hot. If you can't hold a finger on the glass, back off.

Suction cup on the warmed edge, gentle upward pull, and slide a pick into the gap the moment one opens. Then work the pick around the perimeter in small strokes, re-heating as you go. It's slow and it's meant to be slow.

Before you lift the display off, check a guide for your exact model and find out which edge the display cables sit behind. Some phones hinge open like a book from one side, some lift from the bottom. Get it wrong, swing the screen a hundred and eighty degrees, and you'll tear the flex cables off. That's not repairable at home.

The battery itself

Disconnect the battery connector first, before any other cable. Always. Unscrew the little bracket, lift the connector straight up with the spudger, and tuck something non-conductive under it so it can't flop back down.

Modern iPhone batteries sit on stretch-release adhesive strips with pull tabs at the bottom. Pull each tab slowly, at a shallow angle, keeping tension steady. The strip stretches to several times its length before it lets go. If you yank it upward it snaps, and then you're on plan B.

Plan B is isopropyl. A few millilitres flooded under the edge of the cell, five minutes, and the adhesive gives up. Don't pry a battery out with a metal tool and don't fold or crease it. If it's fighting you, more alcohol and more waiting.

Seat the new cell, connect it, and power the phone on before you glue anything down. Testing before sealing is the habit that separates a clean repair from doing the whole job twice.

Why screens are the harder call

On an iPhone, a non-genuine screen costs you True Tone unless the shop or your kit includes a programmer that transfers the original panel's data chip. Recent models will also throw a notification telling you an unknown part is fitted. Face ID survives a screen swap on current iOS versions, but the flood illuminator and dot projector assembly has to be transferred across carefully, and damaging it means Face ID is gone permanently. No repair, no workaround.

Aftermarket panels vary enormously. An "incell LCD" replacement for an OLED phone is cheap and it looks it: blacks go gray, off-angle viewing is poor, and you'll notice every day. "Soft OLED" replacements are closer to original and cost more. Read the listing properly, because sellers are vague on purpose.

Samsung is a different animal. On most Galaxy phones the screen is bonded to the frame, so the sensible repair is a full service-pack assembly that includes the display and chassis together, and you migrate your boards across. It's more work up front and a far better result than trying to separate a curved OLED from its frame. On Galaxies the back glass also comes off first, and that adhesive is the worst you'll meet.

Some Pixels are similarly frame-bonded. Check what the actual replacement part looks like before you commit. If the part is just a loose panel for a phone whose screen is glued to the chassis, walk away.

The small things that ruin good work

Overtightening. These screws want firm, not tight. Strip a bracket screw and you'll be drilling it out.

Pinched cables when you close it. Route every flex flat, seat every connector until it clicks like a tiny popper, and check nothing is sitting proud before you press the display home.

Skipping the small brackets. The metal covers over the connectors aren't cosmetic. They're what keeps the connector seated when the phone is dropped.

Cleaning up. Old adhesive comes off with isopropyl and patience. New gasket goes on a dry, clean frame or it won't hold.

And test everything before the final press: touch across the whole panel including the far corners, both cameras, the earpiece, the proximity sensor by making a call and holding it to your ear, the ambient light sensor by cupping the top of the screen.

When to just pay someone

A swollen cell. A phone still under warranty. A phone you need working tomorrow morning. A model where the part costs nearly as much as the repair quote. None of those are failures of nerve, they're arithmetic.

But an out-of-warranty phone that's three years old, holding half a charge, with the owner already eyeing a replacement? That's the perfect first patient. The downside is a phone you were about to give up on anyway, and the upside is two more years out of hardware that's otherwise fine.

Do that job once and the next one takes half as long. Your son's phone, your wife's, the one in the drawer with the cracked corner. The tools cost what they cost whether you use them once or twenty times.