1 Checking Factory Seals

The very first thing to check is the presence of factory seals. The packaging must be sealed.


2 Checking the Sensitivity of the Touchscreen

To check the touchscreen for functionality, you do not need special programs. It is enough to run the application associated with typing (for example, notes or messages) and type few lines. If there are a lot of typos or letters from a certain area do not appear, it is possible you have defective devise in your hands.


3 Check Sensors

In modern devices there are many sensors that are responsible for movement, it is worth checking these functions. You can open the pictures or videos, after that tilt the smartphone in front of you, check how correctly and quickly it reacts to the user's movements.


4 Check for Broken Pixels

You can start the camera and take a picture of a sheet of white paper. It is desirable to be in a well-lit place. After that it is worth enlarging the image. If there are multi-colored dots on a white background, then a low-quality module with broken pixels has come across. You can also download a special application for checking dead pixels. For example, Dead Pixel Test.


5 Checking the speakers

Typically, a device has a basic set of tunes. With their help, you can check the speaker, and at the same time the operation of the headphones by connecting them to the phone.


6 Checking Charge Port

You can also make sure that the interface port for charging is working properly and is charging the device, furthermore you can check battery health also in setting menu of most modern phone.


7 Wi-Fi Testing

It is worth checking the work of Wi-Fi by turning on the wireless module and connecting to the access point, if there is one nearby. You can try to move away from there, the smartphone should maintain communication within a reasonable range (15 meters), without breaking the signal.


8 Battery Check

If the smartphone is new, you can’t worry about the battery. However, to reassure yourself, you should check the battery if you purchased a device with access to the battery compartment. Usually the area next to the battery gets a white sticker. If moisture has got into the inside of the device, then this sticker will be red, it will immediately be noticeable.


9 Service Code

Smartphones often have a special menu with which you can quickly check all the key parameters. To do this, in a regular “dialer” you need to dial a special code, which depends not only on the brand, but also on the model. Therefore, such a code is better to clarify in advance.