Before you buy a new cell phone or new tablet, please try the following procedure to repair your device. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before factory reset. It is impossible to recover your data after doing a hard reset, so online backup is always important. For all of your data, a backup should be done on an external device, hard drive, raid system or media. With or without insurance, if your cell phone lost, damaged or stolen at least your invaluable data is backed up in a safe place. If you are about to sell your phone and you want to wipe your personal data, or if your phone affected with virus you have to do a hard reset. In some cases, you can delete the forgotten password or lock pattern from your device as well. All information is for devices with stock based ROMs. If you are using rooted device, always back up your EFS folder first, containing your IMEI info, etc.!


T-Mobile myTouch 4G hard reset

If the phone is locked, frozen, or unresponsive, you can  reset it using the hardware buttons instead of the menu. To perform a hard reset using the hardware keys, follow these steps:

Note: A hard reset restores the original factory settings and  erases content, including downloaded ringtones, images, programs, and contacts stored in the internal memory. This feature allows for resetting of sound profiles, display settings, and phone or memory card settings. However, if you want to try resetting some factory settings without losing any data, then clear system cache before a master reset.

1. Save any open files, and back up all  necessary data on the internal memory if the device is responsive and can synchronize files.
2. If the phone is plugged into the  charger or USB cable, unplug it.
3. Remove the battery.   
* Important: Removing the battery is required. Turning off the phone with the Power key does not work, because of the Fast Boot feature.
4. Re-insert the battery.
5. Press and hold both the Volume Down key and the Power key. Do not release the volume key, continue on to step 6.
6. Release the Volume Down key when the three Android images appear on the bottom of the screen. The following options dsplay:      
* FASTBOOT
* RECOVERY
* FACTORY RESET
* SIMLOCK
* IMAGE CRC
* Note: If the you are stuck on a screen that says 'HBOOT' and 'FASTBOOT' without any other options to choose from, it means you have pressed the Back button. To get to the regular options, press either the Power key on HBOOT or the Back button.
6. Press the Volume Down key twice to select FACTORY RESET.
7. Press the Power key to initiate the master reset.
8. Wait as the device displays the boot up screen, then shows a picture of arrows above a device with a progress bar. It then restarts.