The Diagnostic Tool is used to test your device's hardware and help troubleshoot issues you are experiencing. If a hardware issue is diagnosed by the tool, your phone may need to be repaired. 

Follow these steps to access the Diagnostic Tool:

1. From the home screen, tap the dialer icon as if you were going to make a call.
2. Dial *#*#DIAG#*#* (*#*#3424#*#*).
3. Read the notification dialog, and press Accept to continue.

These tests are available in the diagnostic tool:

1. Audio Test: checks the functionality of the receiver, both speakers, and the microphone. Follow the instructions to cycle through each test:
   Receiver test
   Top speaker
   Bottom speaker
   Both speakers
   Mic test
   2nd Mic test
   
   
2. Backlight Test: checks the operation of the backlight. Follow the instructions to cycle through each test:
   Off
   On
   
   
3. Barometer Test: checks the functionality of the Barometer sensor. Either a PASS or FAIL message will display.
   
   
4. Bluetooth Test: checks the functionality of the Bluetooth radio on the device. Pllace any Bluetooth device in discoverable mode. The test will then take you to the Bluetooth settings to complete the pairing process.
   
   
5. Button Test: prompts you to press the following buttons to check for functionality:
   Volume Up
   Volume Down
   Back (to test the haptic bar)
   
   
6. Charger Test: checks the charging functionality of the device. If the device recognizes the charge, a lightning bolt will display in the battery icon.
   
   
7. Flashlight Test: checks the camera flash. Follow the instructions to cycle through each test:
   On
   Off
   
   
8. G-Sensor Test: checks the G-Sensor on the device, used for automatic screen rotation. Place the device on a flat surface. If the G-Sensor is operating properly, the text will turn green and will indicate a PASS.
   
   
9. Headset Test: checks the headset functionality on the device. Plug in a headset into the 3.5mm headset jack, and cycle through each test:
   Headset pick-up button (if applicable)
   Headset test
   Microphone test (if applicable)
   
   
10. LED Test: checks the LEDs on the device. Follow the instructions to cycle through each test:
    Orange LED
    Green LED
    AP Key LED (haptic key backlight)
    
    
11. Light-Sensor Test: checks the light sensor, which is used to automatically adjust the screen brightness. Follow the instructions cover the light sensor with your hand. If the light sensor is operating properly, the text will turn green and will indicate a PASS.
    
    
12. Line Drawing Test: checks the touch screen functionality. Follow the prompts to draw lines on the screen and test the functionality.
    
    
13. P-Sensor Test: this checks if you have the phone close to your face, so that it can lock the screen, dim the display, and disable the touch screen functions when holding the phone to your face while on a call. Follow the instructions and cover the light sensor with your hand. If successful, the screen will dim.
    
    
14. SD card + Camera Test: provides an instruction for how to insert the SD card and then activates the Camera. It is the same as starting the camera normally.
    
    
15. Vibrator Test: checks the vibration feature of the device. Follow the instructions to cycle through each test:
    Start
    Stop
    
    
16. Wi-Fi Test: checks the functionality of the Wi-Fi radio on the device. Please ensure a Wi-Fi access point is available. The test will then take you to the Wi-Fi settings to complete the connection process.