Soft Brick, Boot Loop

This is a brief tale of disaster barely averted.  If you are looking for a solution, I can’t promise that there is one below.  My Samsung GT-N8013 tablet suddenly restarted yesterday and entered the infamous bootloop.  I was able to fix my tablet but I am pretty sure it was entirely down to luck.

The Boot Sequence

When Android boots up, there are two potential break points.  The first is what’s called the Download screen.  On the N8013, you access it by pressing the POWER button while pressing the Volume Down side of the volume button.  When the screen opens, release the buttons.  You will be prompted to cancel (Volume Down) or continue (Volume Up).  If you have the ability to flash a file here, like TWRP recovery, you’d press Volume Up.

Normally, in a boot loop, you can at least get this far.  Unfortunately, while I could see the screen asking me to cancel or continue, the loop kicked in almost instantly and I couldn’t use Odin.  At first.

The next breakout is the Recovery menu.  To access this, you hold down the POWER button and press the Volume Up side of the volume button.  After the Samsung screen appears, it will disappear and be replaced with a short menu allowing you to return to a factory default.  Needless to say, I couldn’t get this far at all.

The Environment

I’m running Marco’s Omnirom custom ROM for the n8013 and TWRP for my recovery.  The tablet is rooted, naturally, and I have Chainfire’s SuperSu installed.  And it had all been quite stable; other than day to day app updates from the Play store, I hadn’t made any system changes.

Here’s where the luck fits in.  The boot loop continued for about 30 minutes.  Sometimes I had the tablet plugged into a USB port and sometimes not.  When I plugged it in, it changed from showing the Samsung startup words to a battery indicator.  This would flash on and off in the same 4 second cycle as the words.  Then a green battery indicator would appear.  Some bootloops are apparently fixed by fully charging the tablet; mine was at nearly 70%.  While charging didn’t seem to affect my tablet.  Once the green battery appeared, holding the POWER button would force it to restart and it would start normally.

This was a temporary state, though.  What it let me know was that I’d lost root, which might have contributed to whatever problem I was having.  I attempted to reload SuperSu from the Play store but it wouldn’t install.  When I restarted, I was back in my bootloop.

A Step Forward

This time, though, when I went into Download mode, it stayed there and showed the normal Do Not Turn Off Your Tablet warning.  I ran to my PC, powered up Odin, and flashed TWRP’s tar file.  When I restarted and held down Power/Up, I could get into TWRP.  I wiped the Dalvik cache, the main cache, and the system.  I flashed GAPPS and the Omnirom from December 2015 successfully and restarted.

When I arrived back at my lock screen, and swiped, I again attempted to install SuperSu.  Again it failed.  This time I decided to download the flashable zip file rather than using the Play store app.  Then I restarted.

And was in a bootloop again.

But now I seemed to be able to goose the bootloop a bit.  It’s hard to know if this was something I could repeat – I didn’t attempt to – or if it was random; I wasn’t willing to test it out for the greater good.  But now, if I forced the tablet into the Download screen (Power/Down), and then immediately into Recovery (Power/Up), it would access the TWRP recovery screen.  Once I was back into TWRP, I decided I would roll back to an older version of Omnirom (June 2015) and flashed SuperSu at the same time.

Success

And for whatever reason, that worked.  I could now get back into my tablet, root was back, and I could restart without entering a bootloop.  If this happens again, one thing I will definitely do is just leave it alone and see if it will bootloop itself enough until it gets to some screen I can work from.  Until I get could to either Download, Recovery, or the OS, it was essentially a hard brick.

Pure luck.  But I’m thankful.  While it was busy looping, I shopped around for possible replacements since I rely so heavily on my tablet.  It was surprising that, even after all these years, the N8013 still has such competitive specs and, with a Lollipop ROM, it is often more current than similar tablets.  I would have missed the size and the S Pen in particular if I’d gone to one of the smaller tablets.