[Galaxy S III Q&A, Help & Troubleshooting] banibhusan:
Hello everyone,

I, like many others here, have managed to brick my galaxy S3 I9300 handset. The problem now is the phone doesn't connect to a network and I get 'unable to mount /efs' when I try to wide data/cache partitions in the recovery mode.

Here is a list of steps I followed to brick my phone:

1. Tried to install CM11 when the phone had stock 4.1.2 ROM by first flashing CWM recovery and then installing CM11 ROM. I had taken the back-up as well, which somehow got lost from the SD card without my knowledge. (Dont ask me how. Its a long story)

2. The phone booted up, but I got some notification related to encryption (I don't remember what was the error) and when I was trying to connect to my Wi-Fi network the phone switched off automatically.

3. When I tried to start it again, the phone got stuck in the SAMSUNG logo. So I went to the recovery mode and I found that its not able to mount the efs partition. So I manually created the efs partition and mounted it using the following commands.

mke2fs /dev/block/mmcblk0p3

mount -w -t ext4 /dev/block/mmcblk0p3

Now the efs partition is mounted.

root@m0:/ # mount | grep efs

mount | grep efs

/dev/block/mmcblk0p3 /efs ext4 rw,nosuid,nodev,noatime,errors=panic,barrier=1,jo

urnal_async_commit,noauto_da_alloc,discard 0 0

And the contents of the efs partition is this:

drwxr-xr-x system system 2014-10-13 00:45 FactoryApp

-rw------- system system 0 2014-10-18 11:00 applied_sdcard_policies

drwxrwxr-x radio system 2014-10-13 00:45 bluetooth

drwxr-xr-x system system 2014-10-13 00:45 carrier

drwxrwxr-x drm system 2014-10-13 00:39 drm

drwxrwxr-x radio system 2014-10-13 00:45 imei

drwx------ root root 2014-10-12 11:47 lost+found

-rw------- radio radio 95 2014-10-12 11:51 nv.log

-rwx------ radio radio 2097152 2014-10-18 11:00 nv_data.bin

-rwx------ radio radio 32 2014-10-18 11:00 nv_data.bin.md5

-rw-rw---- system system 108 2014-10-13 00:39 ss_data

drwxrwxr-x radio system 2014-10-13 00:39 wifi

4. After manually creating and mounting the efs partition, the phone booted up but I got the generic IMEI (004999010640000) and no network signal. Then I booted up the phone in recovery mode and I still get the 'unable to mount /efs partition' while trying to wipe data/cache partition.

5. Then I flashed the 4.3 STOCK ROM on the phone but I it still didn't solve the problem(I didn't think it will anyways) and the phone is now in factory reset mode (which is pretty much expected). Here is the details about the firmware versions on the phone.

AP: I9300XWUGML4

CP: I9300XXUGMK6

CSC: I9300ODDGML4

I did flash a different kernel and modem version as per this link

http://xdaforums.com/galaxy-s3/help/emergency-calls-solved-t2748393

From what I understand, I think the baseband and kernel versions are in sync with the efs partition format. Please correct me if I'm wrong.

I came across many other solutions to try but I don't want to further risk any damage to the phone, hence I thought its better to ask the experts here. I took it to a repair shop where they said, I've got two choices: a) A complete format with some hardware box to restore the IMEI and b) Install a new motherboard which should definitely fix the problem.

Now I'm not sure exactly what's the issue and I'm more helpless because I lost the back up of my working image. Most likely the efs partition is corrupt or if its not corrupt then the problem could be with the software as well. I desperately need your expert opinion on whether the phone can still be fixed or it needs to be sent for repair.

Any help on this would highly appreciated.

Regards