What To Do When Samsung Galaxy S3 Won't Turn On [Troubleshooting Guide]

This post is a troubleshooting guide to help you determine the cause why your Samsung Galaxy S3 will not turn back on. Once you know what the reason is, that's the time you can come up with procedures to bring the phone back to life.

Software Glitch

This includes glitches or issues caused by third-party apps, pre-installed apps and the Android system itself. This is the easiest and safest way to start your troubleshooting with not to mention you don't need some tools to do so.

The following procedures will help you determine whether the cause of the Galaxy S3 not turning on is software-related or not. But again, I want to remind you that the goal of this post is to turn on your phone. If we'll know what caused the problem, we'll know how to solve it.

Boot to Safe Mode

Safe Mode is where all third-party apps and services are disabled leaving pre-installed ones and core services running. This procedure is necessary so you will know if the cause of the problem is one of the third-party apps.

1. Turn Galaxy S3 off.
2. Press and hold its Power key until the 'Samsung Galaxy S III' logo appears.
3. Immediately after releasing the Power key, press and hold the Volume Down button until the phone finished restarting.
4. 'Safe Mode' will be displayed on the lower left corner. If you can reach this far, then your problem has already been solved.

In case Safe Mode procedure won't work on your Galaxy S3, try the next procedure.

Boot to Recovery Mode

You will have to use three hardware keys to be able to successfully boot the phone to the Recovery Mode. Here's how…

1. Turn the Samsung Galaxy S3 off.
2. Press and hold the following keys until the phone vibrates: Volume Up, Home, and Power keys.
3. Immediately after the phone vibrates, release the Power key but continue holding the other two buttons until Android System Recovery screen appears.
4. If you can reach this far, there is a chance that one of the core apps or services has gone rogue, so try wiping the cache partition.
5. Using the Volume Down key, highlight the 'wipe cache partition' option and press the Power key to select it.
6. Once the wiping is finished, highlight the 'reboot system now' option and press the Power key to select it.
7. If the phone boots up normally after this, your problem has already been solved. Otherwise, continue with other troubleshooting steps below.

Drained Battery / Defective Charger

You may not have known that your phone's battery was already drained. So, by the time you discovered it was off and hit the Power button, the Galaxy S3 won't respond simply because there isn't enough juice to power its components. To rule out this possibility, follow these steps:

1. Pop the back panel open and double-check if the battery was well-placed.
2. Plug the charger and let the phone charge for at least 5 minutes.
3. If you can see the charge indicator, your phone is just fine. You can try turning on the phone normally while charging. 
4. In case you cannot see the indicator, try to wiggle cable and check the microUSB port to see if it is not damaged. If it's a cable or port issue, wiggling the cable may randomly display the indicator.
5. After doing the previous step and you still can't see the indicator, try plugging the cable to a computer to rule out the possibility that your charging unit has been busted. 
6. If still can't, you should consider using a different (yet original) charger. 
7. Should the new charger fail to solve the problem, try using a different battery for your Galaxy S3.
8. With the new battery and charger and still your phone won't turn on, inspect the phone battery receptors to see if one was misaligned. If everything looks good and the problem still continues, proceed to the next troubleshooting steps.

Power Switch Problem

If the problem was not in the software nor in the battery and charger, and the phone won't vibrate when you pressed the Power switch, then there is a possibility that the Power switch is the problem.

The Galaxy S3 should respond when you press and hold the Power button either in the form of vibration or the screen would light up. If neither of these two won't happen, then you should consider inspecting the Power switch or have it checked by a technician.

Hardware Issue

This is a dead-end for almost all Galaxy S3 owners whose phone won't turn on no matter what they do. While the term "hardware issue" seems to be a very simple problem, it's not. "Hardware" is a collective term for every physical component found inside and outside of the phone including the CPU, RAM, internal storage, etc. If one of these components won't function well, the phone won't switch on.

After following all procedures above and your Galaxy S3 still refuses to turn on, you must bring it to the store where you bought it or have it checked by an authorized technician. I want to emphasize the word "authorized" because these technicians can actually recommend replacement and when they are the ones handling the phone, you cannot compromise the warranty of your device.

Bottom Line

No one wants to go through all these hassles just to be able to send a text message, make a call or browse the web. But the fact is, technology isn't perfect and so is your Samsung Galaxy S3. The point of this post is to walk you through exhausting all possible ways to determine the problem and eventually fix it. If you can't, employ the services of technicians who are well-trained to deal with this problem.

I hope that this article may have, somehow, helped you. Have a great day, guys!