A laptop and a phone are not checked in the same order. Powering on a laptop commits you to nothing. Activating a phone changes your position — who you deal with and which rules apply both shift once the device is live on a network.
So this guide splits at activation.
What it covers is when to look at what. The rest lives elsewhere.
- Which counter to go to when you find something → Who to go to when a new phone has a fault
- Turning what you found into a record a seller acts on → How to record a fault so the seller takes it seriously
If the phone you are checking is the phone you are reading this on, you can work straight through. These checks run in the browser with nothing to install, and most of them work on a phone.
Before you activate
There is no hurry to activate. The display, the sound and the physical condition can all be checked with the phone simply switched on.
Here is what does and does not need a live line.
| Works without activation | Needs a live line |
|---|---|
| Display: dead pixels, tint, touch | Call quality |
| Speakers and microphone | Texts and mobile data |
| Cameras | Carrier features |
| Physical condition, accessories | Some biometric setup |
| Vibration, buttons |
The left column is where most early faults turn up. Clearing it before activation leaves you with more options if something is wrong.
If a shop offers to activate it on the spot, it is reasonable to check the screen first. It takes a few minutes.
Opening the box
The IMEI should match in three places
Check this first. The IMEI on the box label, in the phone’s settings and on the warranty card should be the same number.
Reading it off the phone is quick: dial *#06# and it appears on screen. It is also in Settings, under About.
If the three disagree, stop and ask before going further. It may only be a mismatched box, but this is the number everything gets checked against later.
Physical condition
In good light, changing the angle as you go.
- Scratches on the display glass, especially near the edges
- Dents in the frame, pressure marks at the corners
- Marks or trapped particles on the camera glass
- Any lifting or step between the display and the frame
- Buttons that feel different from one side to the other
What came in the box
- Charger and cable, or on many models the cable only
- SIM tray tool
- Manual and warranty card
- A case or screen protector if the listing included one
Anything missing is easier to raise before activation.
Five minutes in the browser
The tools take over here. Nothing to install, no account, and nothing is saved.
Dead pixels — full-screen solid colours to find dead and stuck pixels. Go through all six. A dot invisible on white often shows clearly on black. This is also when to look for uneven tint or patchy brightness.
Touch response — drag a finger across the whole display to find areas that do not register. Pay attention to the edges and corners. A panel that works perfectly in the middle can be dead along one border.
Speakers — left and right played separately. Many phones use the earpiece as one of the stereo channels, so a side that is silent or noticeably quieter shows up immediately.
Microphone — watch whether the input level actually moves. Phones carry several microphones, and one can fail while calls still sound fine and only recordings come out wrong.
Camera — check the front camera produces a picture and see what resolution it negotiates. Test the rear cameras separately in the camera app.
To run the whole set in sequence, use the full check. It asks which device you are on first, so choosing a phone gives you only the checks that apply.
If something looks wrong, photograph or record it there and then. The results screen is not saved.
Once it is activated
Calls. Make a real one and confirm both directions — that you can hear them and they can hear you. Try speakerphone too; the earpiece and the loudspeaker are different components.
Mobile data. Compare speed against another phone in the same spot. Consistently slower or frequently dropping points at the antenna.
Wi-Fi and Bluetooth. That they connect, and that they stay connected.
Charging. That the percentage actually climbs, on wireless too if the model supports it. Watch whether it gets unusually hot while charging.
Biometrics. Enrol a fingerprint or face and unlock ten times or so. Working once is not the same as working reliably.
After three days
Some faults need a few days to appear. Do not treat a clean first day as the end of the check.
Whether the battery lasts a day. The first days are distorted by restores and app installs, so three days in gives a truer reading. Note anything that drains unusually fast or drops sharply at a particular point.
Heat. How warm it gets under load — gaming, or recording video. Too hot to hold comfortably is outside normal.
Waking from sleep. Whether the screen is slow to respond, or touch lags for a moment after unlocking.
Dropped calls. In one location it is probably coverage. Repeating across several locations points at the phone.
Cameras. Shoot in daylight and at night, indoors and out. Some faults only appear in particular conditions — focus that will not settle, or a smudge that shows against bright backgrounds.
Once more before the window closes
Run through it again before the return or exchange window ends. The point this time is to re-check what you looked at on day one. Something can develop that was not there at the start, and catching it now means you still have options.
Find out when your window ends and put it in your calendar. Where you bought it decides which window applies — Who to go to when a new phone has a fault sets out the difference.
Why not do it all at once
Splitting it across days is deliberate.
What day one finds is a fault that was always there: display, sound, condition, contents. These are the easiest to argue.
What day three finds is a fault that emerges in use: battery, heat, waking from sleep. No amount of care on the first evening will surface these.
Nothing catches both kinds in one sitting. Hence the order, and hence each step being short.
ReturnCheck does not judge whether a device is faulty. It helps you record what you saw and heard, and no further. The conclusion and the conversation with the seller are yours, which is why you choose each result yourself.