Rick Maybury is on hand to offer advice to a reader frustrated with their non-starting phone
My Galaxy S3 has suddenly stopped working; a few hours earlier I was able to send and receive text messages. It will not charge (although the battery was at 50 per cent before it happened); I removed the battery and put it back in again. I connected it to my computer but there is still no sign of life. Have you any ideas?
David Sample, by email
In spite of that 50 per cent charge reading, a flat or faulty battery is the prime suspect. If you do not have a replacement to hand, plug the phone into known working mains or car charger (not your PC) for half an hour and try again. If it still refuses to boot up remove the battery but do not replace it for at least 15 minutes. While you are waiting press and hold the power button for 30 seconds and this will remove any residual charge held by components inside the phone. If, when the battery is replaced, it is still lifeless try a Safe Mode restart by pressing and holding the power button for 10 seconds or until the Samsung logo appears, at which point release the power button then quickly press and hold the volume-down button. With luck it will continue to boot into Safe Mode. When the Home screen appears go to Settings > Applications and remove the most recently installed apps, as one of these may be causing the fault. If the phone will not start in Safe Mode the last DIY option is to try and boot into Recovery Mode and wipe the phone’s cache memory; do not worry, this will not erase any personal data or files. Press and hold the Home, volume-up and power buttons. After a few seconds it should vibrate and when the Samsung logo appears on the screen release the power button, but keep pressing the Home and volume-up buttons until the Android Recovery menu appears. Use the volume up/down buttons to select Wipe Cache Partition and press the Power button to confirm. If successful this will take a few minutes, select reboot now and see if that works. If not it is time to seek expert assistance.
Source from: http://www.telegraph.co.uk