Resetting the T-mobile G1 Google phone deletes all data, including downloaded applications, and resets the phone back to its initial state before you turned on the phone for the first time. Important Make sure to back up important data you have on the phone before you perform a factory data reset.
T-mobile G1 Android hard reset
1. The device must be powered OFF to G1 hard reset. Note: If the device is not responsive and does not turn off, remove the battery and re-insert it. 2. Press and hold the Home button and the Power button at the same time. 3. Keep holding Home and Power together for at least 25 seconds, even if the "Startup" screen appears. 4. Release the keys when you see a black screen with a warning sign. 5. Slide the keyboard open. 6. As a shortcut, press ALT+W to factory reset the device. If this does not work, continue with the below steps. 7. Press ALT+L. 8. Press Alt+W for 'wipe data/factory reset'. 9. Press the Home + Back key. Note: You can also remove the battery and re-insert it.
1. Press HOME > MENU, and then touch Settings. 2. Scroll down the screen, then touch SD card & phone storage. 3. Navigate to the Internal phone storage section, then touch Factory data reset. 4. On the Factory data reset screen, touch Reset phone. If prompted, enter your screen unlock pattern, then touch Erase everything.
Tip If your phone hangs or freezes, remove the battery, then wait for a few seconds, and then re-install it. After re-installing the battery, turn on the phone.
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.
BCMath lib not installed. RSA encryption unavailable