[Galaxy S III General] majin:
This guide is for the DoCoMo SC-03E (alias DoCoMo Samsung Galaxy III Alpha) owners that wish to unlock their phone, making it SIM Free (SIM Unlock.- Network Unlock), but getting back the original ROM firmware.

Usually, plugging in a SIM card different from the DoCoMo's ones, you will get the request of a "Network Unlock Code".

That because actually the phone is SIM Locked.

The official way to get that code is to go to a DoCoMo Shop and pay about 3100 yen.

Then, officially, you can get keeep a SIM-free phone (SIM Unlock.- Network Unlock), even if you did some ROM update.

Before the release of the last ROM (MB1), the devices with LK5 ROM on board were easily "unlockable" for free just typing some codes by dialpad and from menu.

Now, this procedure is no more avaliable.

Since the dowload of the LK5 ROM is still not available for a roll back, we did find a walkaround to get the a roll back just for the radio part firmware for performing the SIM unlock on the SC-03E.

So, if your phone still has the LK5 firmware, go directly to "STEP 4" on this guida OR try with this Guide.

If your phone has MB1 firmware or newer ones, follow the guide on this page from STEP 1.

REMEMBER TO MAKE A BACKUP OF YOUR DATA, because you are going to perform MANY HARD RESET (alias factory reset).

The unlock should be stay even if you will get official ROM updates.

By this guide, more, the ROM couter (visible in Download Mode) will not increase.

[size=+1]Step 1: DOWNLOADS & UNPACK[/size]

Download the Factory Firmware (stock) Jelly Bean 4.1.1 MB1 ROM from [thanks to davidcsv], then unpack "somewhere on your PC".

Download the Pre Rooted stock ROM Jelly Bean 4.1.1 MB1 ROM (alternative link here) [thanks to davidcsv], then unpack "somewhere on your PC".

Download modem.bin-LK5.rar parts from the bottom of this post and unpack "somewhere on your PC".

Download Odin3-v3.04.zip from the bottom of this post and unpack "somewhere on your PC".

[size=+1]STEP 2: FLASHING "Pre Rooted stock ROM Jelly Bean 4.1.1 MB1 ROM"[/size]

Switch off the phone

Unplug SIM Card and micro SD card

Enable the option in Settings -> Developer Options -> USB Debugging

Restart smartphone

On the PC, close Kies and any related process

Launch "as Administrator" Odin on PC

Plug USB between phone and PC

Wait for recognizing

Switch off the phone

Unplug USB from the smartphone.

Put the phone in Android System Recovery mode (press Volume UP + Home Button + Power Button at same time for a while)

Perform "Wipe Data/Factory Reset" and "Wipe cache partition"

Perform "Reboot System now"

NOW, BEFORE YOUR PHONE WILL START AGAIN, put the phone in "Download mode" (press Volume DOWN + Home Button + Power Button at same time for a while), then press VOLUME UP

Plug USB between phone and PC

Wait for Odin recognizing the phone

On PC, insert the Pre Rooted stock ROM Jelly Bean 4.1.1 MB1 ROM image "SC03EOMAMB1_RR20130322.tar.md5" into the Odin window in the PDA field

Start flashing

Waith for the phone rebooting

Perform Factory Reset from the phone

[size=+1]STEP 3: FLASHING "modem.bin" image from LK5 Rom[/size]

Switch off the phone

Unplug SIM Card and micro SD card

Enable the option in Settings -> Developer Options -> USB Debugging

Restart smartphone

On the PC, close Kies and any related process

Launch "as Administrator" Odin on PC

Plug USB between phone and PC

Wait for recognizing

Switch off the phone

Unplug USB from the smartphone.

Put the phone in Android System Recovery mode (press Volume UP + Home Button + Power Button at same time for a while)

Perform "Wipe Data/Factory Reset" and "Wipe cache partition"

Perform "Reboot System now"

NOW, BEFORE YOUR PHONE WILL START AGAIN, put the phone in "Download mode" (press Volume DOWN + Home Button + Power Button at same time for a while), then press VOLUME UP

Plug USB between phone and PC

Wait for Odin recognizing the phone

On the PC, insert the "modem.bin" image into the Odin window in the PHONE field

Start flashing

Waith for the phone rebooting

Perform Factory Reset from the phone

Wait for the phone rebooting

[size=+1]STEP 4: SIM UNLOCKING / NETWORK UNLOCKING on DoCoMo SC-03E[/size]

Switch off the smartphone

Insert your DoCoMo SIM card

Switch on the smartphone

Enable the option in Settings -> Developer Options -> USB Debugging

Log-in into Google Play Store

Download and install "ServiceMode Shortcut" (free) from Play Store (here)

Be sure that the option in "Settings -> Developer Options -> USB Debugging" is enabled

Launch ServiceMode Shortcut

Go to 'Service Mode' -> ‘[1] UMTS’ -> ‘[1] Debug Screen’ -> ‘[8] Phone Control’ -> ‘[6] Network Lock’ -> ‘[3] Perso SHA256 OFF’

Wait for about 30 seconds

Press ‘Menu’ (left touch key) and select ‘Back’

Select ‘[4] NW Lock NV Data INITIALLIZE’

Wait for around one minute

Switch off the smartphone

Insert the "not officila SIM" into the phone

Switch on the smartphone

Waith for a while and check if the smartphone detects the network signal

[size=+1]STEP 5: FLASHING "Factory Firmware (stock) Jelly Bean 4.1.1 MB1 ROM"[/size]

Switch off the phone

Unplug every SIM Card and micro SD card

Enable the option in Settings -> Developer Options -> USB Debugging

Restart smartphone

On the PC, close Kies and any related process

Launch "as Administrator" Odin on PC

Plug USB between phone and PC

Wait for recognizing

Switch off the phone

Unplug USB from the smartphone.

Put the phone in Android System Recovery mode (press Volume UP + Home Button + Power Button at same time for a while)

Perform "Wipe Data/Factory Reset" and "Wipe cache partition"

Perform "Reboot System now"

NOW, BEFORE YOUR PHONE WILL START AGAIN, put the phone in "Download mode" (press Volume DOWN + Home Button + Power Button at same time for a while), then press VOLUME UP

Plug USB between phone and PC

Wait for Odin recognizing the phone

On PC, insert the Factory Firmware (stock) Jelly Bean 4.1.1 MB1 ROM image "SC03EOMAMB1_SC03EDCMAMB1_SC03EOMAMB1_HOME_REV00_user_low_true.tar.md5" into the Odin window in the PDA field

Start flashing

Waith for the phone rebooting

Perform Factory Reset from the phone

Switch off the phone

Plug in your favorite SIM card

[size=+1]STEP 6: Firmware status check-up by Kies[/size]

Switch on the smartphone

On the PC, launch Kies

Connect the smarthpone and PC via USB

Wait for recognizing

If everything is fine, you have an unlocked phone and Kies recgnize the smartphone with the official "full" "MB1" ROM on board (PDA:MB1 / PHONE:MB1 / CSC:MB1).

[size=+1](OPTIONAL) STEP 7: OFFICIAL UPDATE/UPGRADE to MC3 ROM[/size]

Since Kies will not show the new MC3 update available (it happens anyway) even if you have MB1 on board, you can choose if to keep your smartphone with MB1 ROM or to update to MC3 official ROM.

If have decided for the second choice, download the Factory Firmware (stock) Jelly Bean 4.1.1 MC3 ROM [thanks again to davidcsv], then unpack "somewhere on your PC" and follow the procedure ONLY at STEP 2, (NO Step 3, Step 4, ...), but using the new MC3 ROM file "SC03EOMAMC3_SC03EDCMAMC3_SC03EOMAMC3_HOME_REV00_user_low_true.tar.md5".

[size=+4]NOTE[/size]​

[size=+3]IF YOU COPY AND PUBLISH THIS GUIDE SOMEWHERE,

PLEASE SAY THE TRUTH ABOUT THE REAL SOURCE: [/size]​

[size=+4]XDA-DEVELOPERS.COM[/size]​

[size=+3]THANK YOU[/size]​