Recover An Unresponsive Device Through Power Cycling
If taken care of properly, most gadgets are pretty reliable. Yet, even the most dependable tech can suffer from a freeze and become unresponsive. Assuming that your device hasn’t experienced a hardware failure, a reliable way to try and get it back up and running is with a power cycle.
For Gadgets With A Removable Battery
If you have a malfunctioning device that either will not power on or has locked up, removing its power source (i.e., its power adapter, battery, or both) is a good place to begin the troubleshooting process. Afterwards, wait several seconds, then, reinsert the power source. Now, try powering on the device to see if your issue is resolved.
The Power Button Long-Press
Many newer, ultra-thin devices now contain non-removable batteries. A power cycle is still possible, but you’ll have to adopt a different strategy that will vary slightly from device to device.
For a Nexus 7 or a Kindle, long-pressing the power button for 30 seconds will force a power cycle and reboot the device. On an iPhone, pressing and holding both the power button and the home button for approximately 10 seconds will accomplish the same task.
If in doubt, a quick Google search for Power Cycle and your device’s name should get the right instructions for your gadget.
No Battery Or Power Button???
If your device has neither a battery, nor a power switch (e.g., a router or a modem), you can power cycle your device by simply unplugging its power cable, waiting about 10 seconds, and plugging it back in again.
These might sound like very simply steps, but they, more often than not, resolve a host of issues with many popular gadgets. Trust me, the next time you have an unresponsive piece of tech and grab that phone to call your resident Geek, give a power cycle a try. He/she will thank you for it ;-).
Source How-To Geek