You may have to perform a reset if your smartphone fails to respond when buttons are pressed or the screen is tapped. Note: Before performing a reset, ensure that your smartphone is not locked. Press any key or tap the screen to see if the phone responds.
Acer E140 Clean boot
A clean boot will restore your smartphone to the factory settings. Warning! You should only perform a clean boot when all other options have failed to restore your smartphone to an operational state. Warning! This will erase all your personal information, any contacts stored on your phone and any programs you installed. If your phone is responding to screen input Open Settings from the Applications tab, then tap Privacy > Factory data reset; click Reset phone and then Erase everything to format your phone.
Acer E140 hard reset using buttons
If your phone is not responding to screen input Turn off your phone, then press and hold the Volume down button and then press the Power key. When your smartphone vibrates, release the Volume down button.
General advice: Before you buy a new cell phone or new tablet, please try the following procedure to repair your device in a software way. First charge your battery, backup your important data if possible and in most cases take out SIM and SD card before doing 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.! Please also note, that a hard reset operation will not unlock your mobile phone's SIM lock or network lock, but it will remove the unlock pattern, remove the user password or PIN password (NOT the SIM card's 4 digit PIN code). Also note that the firmware version will not be affected in any way, it will not be downgraded, it will remain the same you are using and if you have rooted your device, root privileges remain also unaffected.
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