24.JUL.2018 / updated: ---:
Secret phone diagnosis: Before you hire to buy a new or used Samsung phone, use this secret code, *#0*#, which must be entered using the dial-up keypad. This will trigger the test window, where you can make sure your phone's built-in functions are working properly.

Quick tip: Some manufacturers block code-based diagnostics on Samsung smartphones and tablets, but most Samsung Galaxy phones have a secret diagnostic mode (on my LG, this feature does not work).

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Secret phone diagnosis

The easiest way is by using the keypad on your phone. Just touch the dial on the Samsung home page by tapping the green button with phone icon.

Using the keypad, enter the code *#0*# (without making a call).

Immediately after entering the last character, automatically appears the test image.

Quick tip: If nothing happens after entering the code, this feature is disabled on the device.

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The most important features

Receiver

Touch the "Receiver" button. A white screen is displayed, accompanied by a whale-hear ringtone or whistling sound. Here, press the phone Back button twice to return to the main test page.

Vibration

The button tests the phone vibration engine. The screen will be black, followed by a continuous vibration. Touch the screen to go back.

Mega Cam

Touch the "Mega Cam" button to test the main camera. Use the volume keys to zoom in or out, then press the camera at the bottom of the screen to take a picture. Save the test image in gallery and touch the Back phone button to return to the main test page.

Sensor

By pressing the "Sensor" button, you can test the accelerometer, proximity sensor, barometer, light sensor, gyroscope, magnetic sensor, and fingerprint scanner.

1. Accelerometer: Controls what motion is detected by shaking the device up and down.
2. Proximity Sensor: Test the proximity sensor of the device. If you cover the phone with your palm, the screen turns green if the proximity sensor works.
3. Barometer: This sensor is primarily responsible for tracking altitudes and helps with more accurate GPS measurements. Touch Barometer Selftest to inform you immediately whether it works or not.
4. Lights sensor: Touch "Light Sensor", and then insert the phone into a different light intensity. Measures three levels, "Level 1" from low to level 3 to extremely bright.
5. Gyroscope: Measures rotation of the device. You can test by touching "Display" or "Charts" manually or rotate, then read the values displayed on the screen.
6. Magnetic sensor: The fingerprint sensor tests the fingerprint scanner. Touch "Standard Scan" to start the test.

Touch

Press the "Touch" button, where you can press the squares individually, or continuously with your finger, where you can watch the squares. Finally, if all the squares or green, you will automatically return to the main page.

Sleep

By pressing the "Hibernation" button, test the sleep mode and the automatic wake up of the device. After awakening, it will return as if you used it normally.

Speaker

The "Speaker" button tests the receiver's audio output, where you can hear a sample song, then press the "Speaker" button to return to the main test page.

Front Cam

To test the front camera, touch the "Front Cam" button. This activates the front camera, where you can take pictures of your face (Selfie). Test photos are automatically stored in the gallery. To return, tap the rear camera button a few times.

LOW FREQUENCY

Test the phone's headset and start the test by pressing the button. You can select 100 Hz, 200 Hz and 300 Hz, and each time you put the ear on the headset of your phone when you hear sounds. After completing the tests, you can return to the main diagnostic page by tapping the phone button twice Back.

Quick tip: If one of the above does not work, it means the device is faulty. Do not buy it.

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