Pre-meet proof

Evidence to request before you spend time travelling.

01Request the full model code and regionAsk for Settings › About phone showing the model code, storage and Android security patch date. Similar names can hide different radios, processors or update schedules.
02Request a low-brightness grey-screen photoA current photo at low brightness can reveal OLED burn-in, tint and replacement-panel defects that bright listing photos conceal.
03Agree on a supervised factory resetConfirm the seller knows the Google and manufacturer account credentials needed to remove accounts before resetting the phone.

Physical inspection

What to inspect under bright light before powering on.

01Inspect the frame, fold and sealsCheck for a bowed chassis, lifting rear cover, loose hinge on foldables, missing SIM-tray gasket and gaps around a replaced display.
02Test the whole panel for touch and burn-inDisplay solid red, green, blue, white, grey and black images, then drag an icon around the perimeter to identify dead touch bands.
03Check USB-C, buttons and camera glassThe cable should insert squarely and charge without movement. Look for chipped lens covers, sticky buttons and stylus damage where applicable.

Function test

A short, repeatable test of the device's expensive functions.

01Run the maker's built-in diagnosticsUse the official device-care or diagnostic screen if available; test speakers, microphones, vibration, proximity, sensors and charging without installing unknown apps.
02Test every selectable lens and video modeFocus on near text and a distant object, inspect corners for blur, and record video while switching only between modes the stock camera supports.
03Confirm calls, data and local radiosTest your SIM if safe, Wi-Fi on both supported bands, Bluetooth audio, NFC detection and GPS. Verify the regional model supports your carrier's key bands.

Account & lock check

Confirm the next owner can activate and use the device normally.

01Remove Google and manufacturer accounts firstWatch the seller remove Google, Samsung, Xiaomi or other vendor accounts in Settings before initiating the reset.
02Set up after reset to expose FRPConnect to Wi-Fi and start setup. Stop if Factory Reset Protection requests an account that was previously synced to the phone.
03Look for enterprise or finance managementReject unexpected work-profile enrollment, device-owner management, lease notices or boot warnings. A normal reset does not guarantee these controls are gone.

Price proof

Comparable facts to record before negotiating or paying.

01Match exact chipset, RAM and regionCompare sold prices only against the same regional model, processor, RAM and storage. Carrier editions and imported variants may trade differently.
02Verify remaining security supportUse the manufacturer's published update policy and the phone's patch date. A model near end of support should not be priced like a current one.
03Record display and battery replacement costsOLED panels and foldable assemblies can exceed the saving on a used phone. Price likely repairs before treating cosmetic damage as minor.

STOP

Walk-away signals

Pause the transaction when one of these cannot be resolved with direct evidence.

Setup after reset asks for a previously synced Google account.
The seller cannot explain an enterprise, lease or device-management message.
The OLED has keyboard, status-bar or navigation burn-in visible on grey.
The model code differs from the listing or does not support your carrier bands.

Safe-use boundary

Evidence helps. It does not certify the device.

DeviceProof is a general private-sale inspection aid, not an appraisal, authenticity certificate, electrical-repair guide or guarantee. Meet in a public place, keep personal passwords private, use only known-safe cables and accessories, and never bypass an owner, activation or organisation lock. Do not open mains-powered equipment or damaged batteries. Stop immediately for swelling, smoke, burning smell, exposed conductors, abnormal heat or threatening behaviour.