Most of us have faced a situation when our smart iPhone 4 becomes unresponsive and cannot be switched on, no matter what we do. The first most important tip is not to get furious, and then try to perform a reset on your iDevice.
A reset can be done in two ways; you can try either a hard, or a soft reset of your iPhone4.
The first one to try implies following steps: you press and hold the Sleep/Wake button together with a Home button of your iPhone 4. In about 10 seconds of holding, an Apple logo should appear on the screen. Only after that try to turn on your phone and see if it runs.
Jailbreaking makes this process a bit complicated, in this case, your iPhone still cannot be back to order. So if you have applied Jailbreaking, or have some Cydia app installed, try to reset your phone as follows:
Connect your iPhone 4 to PC and start iTunes. Still press Sleep/Wake button and a Home button simultaneously for about 10 seconds, till the logo appears on the iPhone screen. Once you see the logo, release the power, but hold the home button for additional 5-10 seconds. Now look at iTunes to check if your device has shown up.
You’ll be notified by iTunes that the iPhone is in a recovery mode. Click OK to continue the restore process. Click and hold the SHIFT button and click on the Restore button. Then select the latest IPSW file for the prompt to appear. iTunes will attempt to bring you back to the manufacturer setting and later will allow you to restore your content from the PC. Each time you apply synch, iTunes makes a backup, so you can chose the latest one from the synch.
As for the soft reset, there are numerous things you can reset in the Settings app, from the Home screen layout to the network settings to all the data on your device.
Tap the Settings icon and chose General Settings. Swipe up to see the bottom of the page and then tap Reset. Tap Reset All Settings to reset the network, keyboard, Home screen layout, and location warnings. Tap Reset in the pop-up window for the confirmation.
To reset specific settings, chose among Network Settings, Keyboard Dictionary, Home Screen Layout or Location Warnings and do not forget to once more tap Reset in the pop-up window for the confirmation.