The problem could be related to an errant app, corrupted Android OS, or bad hardware. Here are the steps you can take if your Android won’t start.
1. Soft Reset
Your device might need a soft reset. On most devices, you can press and hold the Power button for about 15 seconds to soft reset.
2. Pull the Battery
For almost any issue where an Android device won’t start, I always suggest to pull the battery (if it’s removable) first and leave it out for about 20 seconds. Reinstall the battery and see if the issue persists. This step may not seem like it would work, but I know first-hand that it has helped numerous Android users.
3. Check for Stuck Buttons
Make sure that none of the buttons are stuck pressed down. Certain cases can cause the Volume, Power, or Home buttons to stick, preventing start up. Try removing the case.
4. Try a Hard Reset
On most Android devices, you can press and hold the “Volume Down” and “Power” buttons simultaneously for about 20 seconds to soft reset the device.
5. Remove Connected Hardware
If you have an SD card or any other items plugged into the device, unplug them. A bad SD card or headset can cause problems on rare occasions.
6. Ensure Device Has Enough Power
If your device won’t turn on at all, or is stuck in a startup loop, it may not have enough power. Attach the power adapter to the device and plug it into a wall outlet. Don’t use a connection to a computer or other device as the power you’d get is not sufficient to power most Android devices on right away.
Another issue could be the actual battery. See if you can borrow a battery from a friend with a similar device and give that a try. If not, you may want to purchase a new or used battery and try it out. Return the battery to the store if it doesn’t help.
7. Start in Safe Mode
If you installed software that isn’t compatible with your device or malfunctions, it can cause the system to hang at a blank screen or continually force close items. In either case, you’ll want to find out how to start your device in Safe Mode. Safe Mode will start the device with only the base software required to start the device. This will usually allow you to access the Android OS so that you can remove whatever app may be causing the issue.
Most devices start in Safe Mode by pressing and holding the Menu or Volume Downbutton while you power the device on. If you’re not sure how to start your particular device in Safe Mode, search the Interwebs or check the documentation provided with your Android device.
8. Factory Hard Reset
If you’ve tried all of the above steps and nothing seems to work, you may want to perform a factory hard reset on the device. Doing so will wipe all data from the memory of the device (usually not SD card data like music or photos).
There are usually ways to perform a factory hard reset using a hardware button combination before the Android OS loads. Look in your manual or search for what the button combination is for your device. They are different for nearly every device. If you’re not sure how to factory reset your device, check the documentation provided with your hardware.
If none of the above steps work, there may be a hardware issue that you are unable to solve yourself. At that point, I would seek help from the manufacturer or the retail store that sold you the device. It is likely that the device has a hardware issue that cannot be repaired without extensive troubleshooting from the manufacturer.