When you buy a used iPhone on a secondary marketplace, it’s not enough just to check that the model and colour is correct. You also have to check its condition to make sure you discover any problems.
When making the purchase online and the seller is shipping the iPhone to you, make sure that you carefully read the phone description, and check the pictures with attention for any possible faults.
If you do have the chance to meet the seller in person and look at the phone before giving away your well earned money, here is a list of what you should check:
The first thing you should do is to remove any screen protector or case and check the general condition of the phone.
Look for any scratches or chips in the screen, and check the condition of the outer casing. Make sure there are no visible gaps or loose joints (not only that this will allow dust to come in, but it will also make the iPhone more prone to any kind of damage).
If it’s an iPhone 3G/3GS, it’s very common for there to be vertical cracks rising from the bottom of the back case (above the charging dock), or around the headphone jack. A reason for an iPhone 3G/3GS back case to be cracked can be the pressure of a bloated battery.
On the iPhone 4/4S, the back case might appear as lifting away from the phone.
Check the frame for scuff marks, and for any other imperfections. Even if you don’t mind a few scratches or other minor imperfections, the price should reflect the amount of cosmetic damage that the device has. There are other important things you shouldn’t ignore when buying a used iPhone. Keep reading.
The touchscreen and LCDApart from checking the screen for scratches and dents, you should also test the touchscreen and LCD for any dead pixels or unresponsive areas.
You need to make sure that the touch screen registers your taps across its whole surface. In order to check this, open Notepad or Safari, and type something. Use the iPhone’s keyboard in all typing orientations: portrait, landscape with the home button on the right, and landscape with the home button on the left. You can also check the swipe motion by opening the Photo app (zoom in on a photo, then swipe your finger over the whole screen – this should move around seemingly with the motion of your finger).
Here is how to test the LCD for dead pixels: upload Safari and open a blank page. Using the white background look for dead pixels. You can also use iPhone Dead Pixel Tester. This will let you set the screen to a solid colour, and you can see if there are any dead pixels or colour issues.
It is important to make sure that the backlight is fine. You’ll notice if it doesn’t work at all, but you can also test it; go to Settings, tap Wallpaper & Brightness and move the brightness slider from one end of the scale to the other.
While in Safari, test the 3G connection by loading a website page. If the connection is good, it shouldn’t wait much even for a complex page to upload.
To test the accelerometer (the sensor that is used to sense movement, speed and direction), turn the iPhone into landscape mode or type something on an app which accepts text input then shake the phone – a dialog box should pop up asking if you want to undo typing or cancel.
The proximity sensors
The proximity sensors should turn off the screen when you bring the phone close to your ear and face. It does that so you don’t accidentally activate the keyboard, the speaker or any other functions while you’re speaking on the phone. You can check if the proximity sensors work properly by placing your palm close to the upper part of the screen (just above the ear speaker).
Make a call and ask someone to call you back. This will help you test the microphone, the ear speaker and the loud speaker.
Test the power button (on top of the iPhone), home button (the round one on the front of the iPhone), silent switch and volume buttons (the ones on left hand side of the phone). Press them a few times, to make sure that they work correctly and aren’t stuck.
Wi-Fi and cell network
Go to Settings, tap Wi-Fi, and check to see if the wi-fi is working. If you can’t activate the wi-fi (it is greyed-out and won’t turn on), chances are there is a problem with the wi-fi antenna or the communication chip on the logic board. This is not something you should ignore. If the wi-fi does turn on, see if it detects networks around you and compare, if possible, with another iPhone.
Insert your SIM card to make sure that the iPhone works on your network (make sure you have the correct size of SIM for each iPhone model). It’s best to use your phone in an area where you know what kind of coverage you used to get.
In order to check the iPhone’s battery life, go to Settings > General > Usage, and check the time since last full charge. You’ll have an indicator for the ‘Usage time’ (the actual time the iPhone has been in use), and ‘Standby time’ (the amount of time the iPhone has been idle).
It would be ideal to be able to fully charge the phone and then let the battery drain to 2–5%. This is how you can check if the iPhone has a reasonable battery life. A normal battery should last for an average of 7–9 hours (usage time). If it’s much less than that, the iPhone might need a new battery.
As with a faulty dock connector, button or headphone jack, a weak battery is not something that should deter you from buying the iPhone. We can replace the battery with a new one in about 20 minutes and it's not very expensive. However, you might consider asking the for a discount in order to cover the repair cost.
External signs of water damage
Ending up with a water damaged iPhone is one of the worst things that can happen after making a second-hand purchase. If the phone has suffered any water damage you might be lucky and the phone might work fine for a long time, but most of the time people experience a series of problems. Corrosion caused by liquid can bring to irreversible damage of the internal components of an iPhone.
Unfortunately, water damage signs are the hardest thing to spot on a first inspection. Unless the seller warns you, or you are able to open the iPhone (which is rarely the case), there aren’t many ways to check it.
There are four LCI (Liquid Contact Indicator) sensors inside an iPhone. If any of these sensors have turned red, it’s a sign that the iPhone has come in contact with liquid or heavy humidity.
Two of the LCI sensors are visible without opening the phone (one is inside the headphone jack, the other one inside the dock connector). There are another two sensors inside the phone, on the logic board.
You can always check the LCI sensors on the headphone jack and the charging dock, using a torch. If all you can see is white, it’s pretty certain that the phone has not come in contact with water, and you shouldn’t worry too much about internal damage.
However, the external LCI sensors get activated quite easily (sometimes even in contact with steam from the shower), so chances are that the indicators are red and the iPhone is still in perfect working order and you have nothing to worry about.
Play on the phone for a while, or make a phone call. If you notice that it gets really hot then that might be another sign of water damage. When a phone is exposed to water or any liquid, a short circuit on the logic board may cause all kind of problems, and can even damage the phone beyond repair.
Go into the Maps app and tap the arrow in the bottom left corner. A pulsing blue dot should indicate your current location. Zoom in on the blue dot and if the surrounding landmarks correspond to your actual location, it means that the GPS is working. If the GPS can’t identify the location, it is probably faulty. Sometimes it might take a few seconds to get an accurate position via GPS as the iPhone first uses wifi networks around you to get the location.
To check the headphone jack and dock connector, make sure that you bring along a set of headphones, a charging cable and a torch.
Plug in the headphones and listen to some music. If you have headphones with microphone and remote, use them to make a phone call to make sure that everything is working ok. You should be able to hear everything clearly.
If there is a problem, check with a torch to see if there is anything stuck inside the headphone jack or if there is any corrosion.
The easiest way to test a dock connector is by plugging the iPhone into a charger to see if the iPhone charges. Before connecting it to the charger, have a look to see if you notice any external damage to the charging port, and use the torch to look for any internal damage or debris. Sometimes, even a considerable amount of fluff from the inside of pockets can prevent the charger from connecting properly.
Another way to test the charging dock is to connect it to iTunes. If the iPhone won’t sync with your computer, it might be because of a faulty dock connector.
Sometimes, a dead battery (in need of replacement), will prevent the iPhone from charging.
Often, the problem is not the charging dock, but the charger itself. If possible, test the iPhone using a few different chargers, and connect it with a USB cable to the computer as well.
Keep in mind: most second-hand iPhones don’t come with a charger.
As with the headphone jack, you are able to check if there is any kind of debris, corrosion or if the LCI sensor is activated.
Take some pictures in order to test both the front and the back camera of the iPhone. Check if the shutter opens and closes properly, test the LED flash and test the ‘focus’ feature by aiming the camera at a scene with marked differences in distance/brightness; the camera should adjust focus/brightness according to where you tap the screen.
If the camera lens is scratched or has some smudges on it, these issues might reflect in the pictures you take. Anyway, it’s not the end of the world. In most situations, replacing the back panel of the iPhone will sort out the problem, so you don’t have to replace the camera itself.
Test both cameras again by recording a short video with each one. Videos should be free of stuttering, and you should be able to hear sound when you play the video back. From the iPhone 4 onwards, all iPhones have a different microphone which records sound while filming. This microphone is also used to improve the sound quality during phone calls. Note that the first generation of iPhone, iPhone 3G and iPhone 3GS don’t have a front camera.
Play some music to make sure the speaker is working. By the way, the iPhone has only one speaker (the microphone is behind the other silver mesh).
Keep in mind that iPhones come in different storage size. Thus, it’s obvious that the price for a 32GB iPhone won’t be the same as the price for a 16GB iPhone (it will vary both on iPhones of the same model, and from one model to another). You’ll want to consider the storage capacity as a relevant factor in your purchase decision, especially if you have a big iTunes library.
Usually the seller should mention the iPhone’s capacity, but if this is not listed in the iPhone’s description, and you’re looking for a certain storage size, ask. If you have the chance, you can check it yourself going to Settings > General > About. Here, together with other relevant details about the iPhone (such as model, serial number, IMEI, network etc.), you’ll find the iPhone’s capacity (both total capacity and available capacity).