[Galaxy Tab 4 Q&A, Help & Troubleshooting] my.faleu:
Hello, my name is Marc-Yvan from Douala, Cameroon and I will tell you the whole story about how I successfully unbrick my Android Tablet. My aim is to share with you some tips about how to recover from a desperate situation of having an unusable tablet.

How I hard-bricked my Tablet:

First of all, let me tell you how I hard-bricked my beloved tablet after trying to unlock it from its original network lock. I got this tablet from a relative who live in USA but it was unfortunately network locked to the AT&T network. So I tried to unlock it by multiple means (by myself). I found a cracked software called “Octopus for Samsung” who was said able to unlock any kind of Samsung phones/tablet. When I tried to unlock my Tablet, the software starts the work and then told me that the device will turn off and turn on after a short time. But the Tablet did not turn on anymore and I spend 02 months trying to bring it back from the grave.

Definition:

Let me explain to you what is called a hard-bricked smartphone/tablet. It’s simply a smartphone/tablet which is unusable, doesn’t turn on (desperate black screen) and doesn’t react to any stimulation. But you have to know that these hard-bricked devices are displayed as unrecognized devices when plugged onto a computer. So a hard-bricked device is not a physically damaged device but is a sort of hardly logically damaged device which cannot boot at all and is not recognized by common flash tools such as Odin, etc.

How I unbricked my tablet:

Lucky Context (GOD’s help):

Fortunately, GOD helps me by guiding me through this situation in order to recover from it in a miraculous manner. I will explain it to you in a couple of points:

1- My Tablet was rooted before the incident. I did it by using an application found in play store: “Kingroot.apk”.

2- My Tablet was equipped with some tools like “Es explorer” and “Terminal Emulator”. You will understand how it fortunately helped me before the incident.

3- The real hand of GOD: In my quest of finding a mean to network unlock my tablet, I tried a method which was asking to save some partitions of the eMMC (A kind of processor memory. Sorry but I’m not an expert ;) ). So I saved it to the memory of my Tablet and then transfered it to a folder in my computer (By using command lines with “Terminal Emulator”). This actually helped me after to revive my tablet.

Advice N° 1 (Prevention)

Before trying to explore the whole abilities of your Tablet by flashing it or trying to network unlock it; Do a backup of the primary boot partition of your eMMC by executing this command in the “Terminal Emulator” of your rooted device:

cat /dev/block/mmcblk0> sdcard/mmcblk0.img

Be careful, this command could save the life of your beloved Tablet. This command will actually copy the primary boot partition of your eMMC in a disk image which has the same name. So you have to keep that disk image in a safe place such as your computer or an external removable disk.

Advice N° 2 (Resolution)

The Story:

In my desperate actions trying to revive my hard-bricked tablet, I read tremendous forum posts and tried countless methods. Which lead me to install a new OS in my computer. It was actually Linux Ubuntu 16.4. I found a method which told me to try to write some kind of partitions images down to an SDCard to boot my Tablet with. But the partitions images proposed by the method didn’t succeed in recovering my Tablet. So some days later, when I turn on my computer, I fortunately found a file opened; it was the primary boot partition image file of my tablet that I saved before the incident (The real hand of GOD). So I decided (Inspired by the Holy Spirit) to try the previous method with the original boot partition image file of my tablet.

The Tip:

You will need an SDCard with a correct format (FAT32) and size (16Gb or 32Gb). You will also need to work in a Linux command line terminal. To write the boot partition image in your SDCard you will have to execute this command line:

sudo dd if=mmcblk0.img of=/dev/sdb bs=1024k status=progress

Note: The sd card may not be sdb though. In order to confirm, before writing, browse to /Dev and look at the properties of sdb to ensure it is in fact there (it might be sda, sdb, sdc, etc...). You can also try to unplug and then plug the SDCard to see the changes.

The Last Step (Eureka!!!)

The last step is just to insert the SDCard into the slot of your Hard-Bricked device, Turn it on and then feel its vibration that will let you know that your mission is completed. Your device is alive again.

Conclusion

The only conclusion that I can give is to NEVER GIVE UP when you are trying to solve a problem. You can be closer to the solution than you think.

Good Luck!;)