Things to check carefully before buying a used iPhone

Recently, many people after buying a used iPhone discovered that the device had serious errors, even though it initially looked shiny and worked normally.

Therefore, it is extremely important to understand the points to check before spending money to buy a used iPhone to avoid losing money or having the device broken.

1. Check battery status: The first step that cannot be skipped when buying a used iPhone

The battery is one of the fastest degrading parts on any smartphone, and the iPhone is no exception. Therefore, before deciding to buy a used device, checking the battery condition should be a top priority.

If you’re not familiar with the concept of “Battery Health,” it’s the maximum charge your battery can currently hold compared to when it first came out of the box. It’s displayed as a percentage in Settings.

For example, if the battery shows 90% health, when you charge it to 100%, it will actually only have 90% of its original capacity. According to Apple's recommendation, when this level drops below 80%, you should consider replacing the battery to ensure performance.

If you buy an iPhone from an acquaintance or trusted source, you can easily accessSetting>Battery>Battery statusto check. However, when buying from refurbished or third-party stores, you need to be more careful. Currently, some sellers can use tricks to fake the displayed battery percentage, making you think that the device has "100% original battery" when in fact it does not.

To check it accurately, use third-party diagnostic software such as coconutBattery (for macOS) or 3uTools (for Windows and macOS). After installing the software on your computer, connect your iPhone via cable, select “Trust” (Trust) when asked on the phone. The app will provide a detailed report, including the number of charges (charge cycles) and actual battery capacity, helping you accurately assess the battery condition before making a purchase decision.

2. Be careful with "fake" screens: Small details that are easy to overlook when buying used iPhones

One of the easiest parts to replace on an old iPhone is the screen, especially if the device has been dropped and refurbished. However, not all screens are as good as Apple’s original components. Many devices are replaced with poor quality screens, affecting the user experience, durability, and even safety.

A simple way to detect a fake screen is to place the iPhone on a wireless charger and unlock the screen. If you see the device automatically touching, opening apps by itself, or responding erratically, it is likely that the device is using a substandard screen, because "fake" screens often cause touch interference and are not compatible with wireless charging.

Also, take a close look at the bezel around the screen. On a genuine iPhone, the bezels are evenly spaced and symmetrical. If the bottom bezel is unusually thick, or the bezels are uneven, it could be a sign that the screen has been replaced with a non-genuine part.

For the iPhone 12 and later, Apple uses OLED panels, which provide vibrant colors and deep blacks. Some repairers replace them with cheap LCD screens, which are easy to confuse. To check, turn on Dark Mode and open the Settings app. If the background is not deep black but dark gray, it is most likely an LCD screen, a sign that the device is no longer original.

In short, while the exterior may look sleek, the screen is still a very vulnerable part of the device. Checking carefully before buying will help you avoid a low-quality device.

3. Don't forget to check the speakers and microphone: Easily overlooked but very important parts

When testing an old iPhone, many people just try listening to the speaker or making a quick phone call to see if the microphone is working. However, the reality is that the iPhone has many speakers and microphones arranged in many different locations, and even a broken part of it can affect the user experience.

As for speakers, the iPhone has two main speakers: one on the bottom near the charging port and one on the top near the earpiece (next to the front-facing camera). To test this, play some music or video, then hold each end of the iPhone up to your ear to see if both speakers produce clear sound. If one side is muffled, crackling, or missing, there may be a problem with the speaker.

With microphones, Apple equips the iPhone with multiple microphones in different locations, including the front, back, top and bottom edges to serve functions such as video recording, FaceTime calls, voice calls, Siri virtual assistant and noise cancellation.

To test your entire microphone, you can open the Voice Recorder app, press the record button, and speak from different angles and directions (in front of you, behind you, above you, etc.). Then, play back the recording to check if the sound is clear and even in all directions.

Checking the speakers and microphones carefully will help you detect potential errors early, avoiding buying a device that has been dropped, exposed to water, or has had substandard components replaced. This is a simple but very important step that many people easily overlook when buying a used iPhone.

4. Don't ignore Face ID: An important but easily damaged feature when buying a used iPhone

One of the features to check carefully on a used iPhone is Face ID - facial recognition technology that helps unlock the device, authenticate payments and log into applications quickly.

However, Face ID can easily be disabled if the phone has had a poor quality screen replacement or the TrueDepth camera (the facial recognition sensor cluster) has been replaced or damaged.

Normally, if Face ID isn't working, your iPhone will display a warning on the lock screen when you boot it up. But don't rely on system warnings alone, double-check to be sure.

The test is very simple:

- EnterSetting>Face ID & Passcode, enter password if prompted.

- SelectSet up Face IDThen follow the instructions on the screen: put your face in the frame and move your head slowly in a circle.

- Once setup is complete, lock your device and try unlocking it with Face ID.

If the setup process goes smoothly and the phone recognizes your face correctly, then the Face ID system is working properly. On the other hand, if there is an error during the setup process or the phone does not recognize your face, it is likely that the camera cluster has been tampered with and the repair will be quite expensive.

Face ID is not only a convenience, but also an important part of the security of the iPhone. So don't forget to check this feature carefully before deciding to buy the device.

5. Beware of Activation Lock: The sophisticated trap that makes you lose money when buying a used iPhone

When buying a refurbished or used iPhone, especially online, you should never skip checking for Activation Lock. If the seller only provides a picture of the device on the “Hello” screen or the initial setup screen, consider this a serious warning sign, it is very likely a stolen iPhone.

Activation Lock is a powerful security feature from Apple that ties an iPhone to the previous owner’s Apple ID account. Even if the device has been erased, you still won’t be able to use it without entering the correct old iCloud password. This means that if Activation Lock isn’t removed, your newly purchased phone will remain stuck on the activation screen, completely useless.

In many cases, crooks will try to sell such devices at bargain prices, preying on the psychology of bargain hunters. But if the seller fails or avoids removing the device from their iCloud account, it is almost certainly stolen. In addition to the risk of buying a “brick,” you may also be tracked by the device’s real owner or reported to Apple, which could lead to legal trouble.

So always ask the seller to turn off Activation Lock before buying. The way to check is simple: go toSetting>General Settings>Transfer or reset iPhone>Erase all content and settings. If the device asks for your iCloud password, it means the device is still locked. The seller must complete this step before you pay.

While buying a used iPhone can save you a lot of money, if you’re not careful, you could end up losing money to scammers. The safest option is to buy from reputable sources, such as an official Apple refurbished store or a retailer with a clear warranty./.