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Boot loop and root help


New member
Jan 3, 2015
I have a sprint Galaxy S3 that powers off when it reaches the unlock screen only when plugged in. When not plugged in it reboots over and over.

I'm not sure what version of Android it's running and I know that matters when rooting.

My questions are;

1) What steps can I take to fix the device so I can get into the actual OS? (I've done wipe cache partition already)
2) Can I root this device by loading files to the external micro SD card only?



Retired Moderator
Feb 12, 2012
0) Check the battery. If it's really bad, it'll retain enough power to start booting, drop voltage enough to reboot, and keep going like that until it dies completely. (A new Anker battery is about $14 on Amazon.) Never (if at all possible) let the battery fall below 40%, except for the first 3 charging cycles. Charge it fully, use it until the phone tells you to recharge it (usually when it falls to 5%-10%) then recharge it fully. Do that for 3 cycles of charge/use.

If you need more battery than 60% will give you (you use 60% to get down to 40% charge), Anker sells 2 batteries and an external charger [charge the battery in the phone and the one out of the phone at the same time] for $26. That way, when the phone battery gets down to 40%, swap them. Now you have 120% of one battery's capacity.

1) See #0. I think that's your only problem. But if you can get to the lock screen with the charger in, you should be able to get into the rest of the phone.

2) As you said, that depends on the version of Android. Plug it in, get to the lock screen, unlock it, go to Settings/General/About device/Kernel. If the date of the kernel is June 2, 2014 or earlier, Towel Root should root it. It's an app. Install it and run it (press the "Make it rain" button) and the phone will be rooted. If it's later, look on Sprint Samsung Galaxy S3 - XDA Forums and see if someone has a rooting method for your version of Android. (Kingo may work, if you have access to a Windows computer.)


New member
Jan 3, 2015
Thanks for the info.

Is this a normal thing when the battery gets old?

I'm trying to fix this for a family friends kid so I don't know how old the battery is but their Sprint contract is up in March so they are w/o a phone for him until then.

The son said he could sometimes get it past the unlock screen but now he can't....seems odd that the battery would do that.

Is there a way to determine what software/baseband and all that the phone is running via other methods besides inside the OS settings?

In Download mode it says
Product Name: SPH-L710
Current Binary: Samsung Official
System Status: Official
Qualcomm Secureboot: Enable
Warranty Bit: 0
Bootloader AP Swrev: 2

In recovery mode it says
Android system recovery <3e>