Guides to checking a device
Step-by-step guides: buying a used iPhone, Android, iPad, laptop or MacBook; checking a device after a screen or battery repair; getting ready for a repair or a sale.
How to check a used iPhone before you buy itCheck a used iPhone step by step: Activation Lock, IMEI, replaced parts, battery health, screen, Face ID, speakers and cameras. With free tests that run in Safari.How to check a used Android phone before you buy itWhat to check on a used Android phone: Google FRP lock, IMEI, Samsung's *#0*# test menu, battery health, OLED burn-in, touch and cameras.How to check a used laptop before you buy itUsed laptop checklist: screen, keyboard, touchpad, battery wear with powercfg, SSD health, fans and temperatures, hinges, ports and BIOS passwords.How to check a used MacBook before you buy itWhat to check on a used MacBook: Activation Lock, company MDM enrollment, battery cycle count, screen coating wear, keyboard, Touch ID and speakers.How to check the screen of a used phone or laptopHow to spot dead and stuck pixels, OLED burn-in, LCD backlight bleed, replacement screens and dead touch zones on a used phone or laptop, with free tests.How to check the battery of a used phone or laptopRead battery health on iPhone, Samsung, Pixel, Windows laptops (powercfg) and MacBooks, and spot swollen batteries, loose charging ports and fast drain.How to check a used iPad before you buy itWhat to check on a used iPad: Activation Lock, school or company MDM, Wi-Fi vs Cellular, battery, LCD backlight bleed, bent bodies and Apple Pencil.How to check a used Samsung Galaxy before you buy itUsed Samsung Galaxy checklist: Samsung account lock, financed phones, tripped Knox, model codes, the *#0*# test menu, AMOLED lines, S Pen and Z Fold/Flip hinges.How to check a used Xiaomi, Redmi or POCO phoneUsed Xiaomi checklist: Xiaomi account lock, global or Chinese ROM, unlocked bootloader, the CIT test menu, AMOLED screen, fast charging and board failures.How to check a used Oppo phone before you buy itUsed Oppo checklist (Reno, Find X, A series): Oppo account lock, official or import, the *#899# test menu, curved screen swaps, SUPERVOOC charging, Find N hinges.How to check used AirPods and headphones before you buyCheck used AirPods, Galaxy Buds or Sony headphones: spot fakes by serial number, remove them from Find My, test left/right sound, ANC, mics and each bud's battery.How to check a phone or laptop after a repairCollecting a repaired phone or laptop: check for a cheap replacement screen, tint, 60 Hz, touch, proximity sensor, Face ID, earpiece and battery before you pay.Before you send a phone or laptop for repairGet ready for a repair: back up, save a condition report as evidence, note the IMEI, Samsung Maintenance mode, your BitLocker key and a proper intake receipt.How to prepare a phone or laptop for saleSelling a used device: back up, send buyers a test report, sign out of iCloud and Google, avoid FRP lock, factory reset, remove payment cards and hand over safely.How to check a new phone or laptopWhat to check on a new device: IMEI matches the box, activated or ex-display, battery cycles, dead pixels, backlight bleed, keyboard, speakers and laptop specs.How to check a used iPhone with 3uTools and Soi MáyUse 3uTools to check a used iPhone: read the verification report, replaced parts and battery cycles, then test the screen, speakers and Face ID in Safari.Dropped or wet phone: what to do and what to checkPhone or laptop dropped or wet: what to do right away, why rice does not help, and how to check the screen, touch, cameras, speakers and battery once dry.Used phone test apps and laptop test software: what to useDo you need an app to test a used phone or laptop? What Settings, 3uTools and apps can check, and what you can test right in the browser, free.