[Galaxy Tab 2 General] billysam:
Well, I have been going through many tab owner problems on this forum who have tried everything on the book to get their tab back running. this experimental process is only for those people who have no option left than to throw away their tab as a dead glorious paperweight or play with it as a Frisbee. hopefully it can recover or at least it can open a new way for getting out of a brick or perhaps be a good learning experience, just for the sake of it. what else would you want to do? if your device is un-repairable? at least this can take a backup for the complete device in a different way though.

So what really is this about?

Well, Samsung tab 2 emmc is pretty much notoriously getting scarier, either it is happening because of flashing a wrong kernel or doing wrong with your tab, or in some cases where people had no clue. A sudden attack and the tab was dead. you may be lucky to get a replacement and get the tab running up again. but not all could be solved and resolved.

but what if we provide the tab a second emmc(your external card emulated and working as an exact image of the internal emmc with all the system files with their partition on it?) sounds good eh? there are 2 sides of this coin. one, our device is not made that way and it's definitely not going to work at all, second, it can work after a little hardware modification provided you have the right files and right tools and a insanely expert brain. Now the chances of this working is like that of flipped coin landing on it's edges. very tricky.

But how we can achieve this then?

Well, there are users on the internet that have some sort of success in this, while it wasn't guaranteed for their device, that this process can work for all and there is definitely nothing like this sort ever found for our device. which is on omap chipset, it's the debrick method. you can't tell unless you are from the development department of Samsung. So, I would say even if it's 0.0000000001 percent of having a chance to work for us. I would like to keep it.

Debrick.img? what does it do? how to get it?

Well, this file is generally taken out from a stock rom from location /dev/block/mmcblk0 which is where pit stores the data for all the partition and from there we can extract all the important parts, including the boot-loader, recovery, cache, hidden, sbl1, sbl2, factoryfs param, modem, EFS, DataEFS to a .img file. (as far as my definition goes for better understanding). please feel free to go through all the post that you can find about the debrick, or if you have more knowledge please share.

I was just going through these posts.

The whole process for sg s3 http://xdaforums.com/showthread.php?t=2660566

http://xdaforums.com/showthread.php?t=1818321 a guide that explains about taking backup of the entire memory block with all partitions or single partition. it's quite old but informative.

fixing a bootloader

http://xdaforums.com/showthread.php?t=2345860

there are different parts to it, first is getting the bootloader written on a external sd card. but we still don't know if our device will be able to treat the external sd card as an internal emmc. it is yet to be found out.

my theory is suppose if we can get out the whole partition along with system written on a external card, can we make the device treat it as a internal emmc? will it then be possible to revive a dead internal emmc tab? there are chances it might. still no practical though and no guarantees for sure.

but it makes you feel better, I managed to get out those partition on a .img file which could be written on a external card as well. basically an image of your emmc. this might be a good backup too for those who would like to be safe in case a emmc bug hits them too.

Now, To get this data we need volunteers to take these files from their working rooted stock rom and upload these files for every model of samsung tab, if they wish to contribute to our community, you are welcome. or at least keep it safe on their disks. although, this process will require atmost care as we are dealing with bootloaders here, and one wrong bootloder and it

won't work, as much as my knowledge goes, there are two- the ics and jb for our tab 2. still there are many other variants and I really have no clue, how to work this out all by myself. so, I would like other great minds share their wisdom upon this and please before sharing files, mention everything you can, right from your

1. Device model number

2. 8gb or 16gb

3. Bootloader(ics or jb)

4. Stock rom, custom rom,

5. firmware

6. Baseband

7. Country and to your name.

Now before pulling out this file, I have a doubt, as I have got few imgs option. there is 128mb, 200mb, 256mb, 512mb and also I have got one img of around 2.17gb as well which is the complete backup I could take out from my device.

I am not sure which one to choose that's going to work. people have mostly used 128mb file to get access to the download mode, I guess in that 128mb, there is enough files needed to boot your device into download mode and recover from hard bricks, but there is no evidence as for now in our device section as to which is suffient for us. So for first try, we take 128mb, and keep doubt aside for one process.

but suppose it's our emmc bug and we want to use the external as a image of the damaged internal, in that case I suppose we need to take out the whole info! is it really possible with the 2.17gb of my device complete data? ah, I would really like to know about the answer myself, in case it hits my device, I would be prepared myself :p

anyways to try this you must have a sd card reader and use a external card of 16gb or 8gb depending upon your device variant (card class 10 required, on others it has high chance of not working at all)

Now the process to extract the file

The script that you need to enter into terminal emulator(download one from playstore) this will backup a 128mb file on your sdcard.

#su
#busybox dd if=/dev/block/mmcblk0 of=/sdcard/debrick.img bs=1M count=128

128MB is arbitrary. on some devices 70MB was sufficient, on our device? maybe or maybe not. please test or help me answer this correctly, if I'm wrong. but untill then, use 128mb, if we fail, we will look for other options.

other dd commands

1. dd if=/dev/block/mmcblk0 of=/sdcard/backup.img

backup whole partitons thus will be large size and takes more time.

2. dd if=/dev/block/mmcblk0 of=/sdcard/debrick.img bs=1M count=70

70mb data from mmcblk0 will be copied to sd card

3 dd if=/dev/block/mmcblk0 of=/sdcard/debrick.img bs=1M count=512

512mb data from mmcblk0 will be copied to sd card

4. dd if=/dev/block/mmcblk0 of=/sdcard/backup.img bs=4096

large size more than 4GB and more time consuming

Procedure

1. Connect the external sd card to the card reader move all the files to your pc and format it.

2. find the correct debrick.img image from post 2.

3. Download and extract this software win iso burner

4. Open the software win32diskimager.exe and browse the debrick.img

5. Successfully Write the debrick.img onto it.

6. Put the sdcard in your device

7. Pray, or do the cha cha, praise the droid lord.

8. switch it on or press power button + volume down/up, whatever you can.

9. if you can then get into download mode, you can try to flash stock firmware or dance your way around.

10. report us back what happened.​