iSupply iPhone buyback check: activation lock, battery and replaced parts
Before you pay for an iPhone you need to know three things: whether it is locked to someone else's Apple ID, what state the battery is in and whether anyone has swapped parts. iSupply Scan reads all of this over USB straight from the phone's hardware, not from what the seller tells you. This page covers what to check at buyback, how the app spots a replaced part, and what it can and cannot tell.
What to check before you buy back an iPhone
iSupply Scan reads everything below in a single connection. Results appear live, every phone in its own slot, up to 48 devices at once.
Activation lock
A phone locked to the previous owner's Apple ID cannot be activated or sold as working without their password. The activation state shows as soon as the phone is connected.
Battery health and cycles
True capacity and charge cycle count read straight from the phone, so you grade the battery honestly and know whether to replace it before resale.
Replaced parts
The display, battery, cameras, Face ID, Touch ID and logic board each carry their own serial number. The app stores them as a fingerprint and reports what changed on the next scan. How it works
Panic logs
System crash logs are decoded into a named sensor and a likely cause, such as the battery, the charging port or the logic board, so a hidden fault shows up before you pay.
Functions and connectivity
Display, Face ID and Touch ID, front and rear cameras, microphone, speaker, Wi-Fi, Bluetooth, taptic engine and proximity sensor.
Model, capacity and IMEI
Model, storage, colour and IMEI are read automatically. After grading you print a label on a Brother QL printer and the unit goes into stock without retyping anything.
How iSupply Scan spots a replaced screen, battery or camera
Every part in an iPhone has its own serial number, which the phone reports in its hardware registry. iSupply Scan reads it for the display, battery, cameras (rear, front, ultra wide and telephoto), Face ID (dot projector and infrared camera), Touch ID, taptic engine, logic board and storage. Which parts can be read depends on the phone's generation.
On the first scan the serial numbers are stored as that device's fingerprint. On every later scan the app compares them and shows one of three results for each part:
- MATCH – the part is the same as at the first scan.
- MISMATCH – the serial number differs, so the part has been replaced since the first scan.
- POSSIBLE FAULT – the part's serial number cannot be read. That can mean a faulty part, a bad connection or a logic board problem, or a part that does not report a serial number at all. Confirm it with a functional test.
In practice: scan every phone the moment it comes in. If a unit comes back on warranty, a new scan shows whether anyone has swapped the screen or the battery in the meantime.
What the fingerprint cannot tell you
The phone holds no independent factory record of its parts' serial numbers, and Apple offers no public interface for factory serials. The reference is therefore the state at your first scan. A match means the part has not changed since then, not that it came from the factory. If a part was swapped before the phone reached you, comparing against the fingerprint will not reveal it on its own.
At buyback, combine the fingerprint with the other data: panic logs, battery health, functional tests and parts whose serial cannot be read. On iOS 15.2 and later, newer iPhones also show their own parts and service history under Settings → General → About.
Questions about checking iPhones at buyback
What do I see on a phone I am scanning for the first time?
What if the phone is locked to an Apple ID?
Do I need the Apple ID password or change anything on the phone?
How much does checking one iPhone cost?
Which iPhones are supported?
Try iSupply Scan on your own phones
One file for Windows 10 and 11 (64-bit), Apple's USB driver included. The app does not start without a licence key – request a free trial key at info@isupply.cz or on +420 703 125 125 (Mon to Fri, 9:00 to 19:00 Prague time). No credit card required.
Phone failed the test? Spare parts are at isupplyparts.cz, and isupply-servis.cz repairs iPhones in Chrudim, Czech Republic.