The Samsung Galaxy S3 is the symbol of Samsung's effort for continuous improvement, packed neatly in one slick and powerful Android device. Though many were disappointed with the fact that it did not bear the currently craved Jelly Bean operating system, a lot of people are still scrambling to bring one home. Many are tempted to go beyond stock experience by installing custom ROMs. The AT&T Galaxy S3 just recently got its share of the CyanogenMod 9 custom ROM, and it's looking good.

XDA Senior Member ChaosMinionX dared to bring the CyanogenMod 9 custom ROM to the AT&T Galaxy S3 and it turned out to be a success. Some bugs and issues are still present, namely, USB functions which are not working, misbehaving Camera Touch Focus, some voicemail issues, and Camera Storage Point issues. Despite those, it still brings to you that pure Ice Cream Sandwich experience, though.

See the requirements and instructions below if you want to install CyanogenMod 9 on the AT&T Galaxy S3 SGH-I717.

Warning

• The instructions in this guide are intended for use with the AT&T Samsung Galaxy S3,model number SGH-I747. Applying these instructions on another device or model may produce undesired outcomes.
• The information in this guide is provided for instructional and educational purposes only. There is no guarantee that these instructions will work under your specific and unique circumstances.
• Use these instructions at your own risk. We shall not hold any responsibility or liability for whatever happens to you or your device arising from your use of the info in this guide.
• Read and understand the whole guide first before actually performing the instructions.

Requirements

• AT&T Samsung Galaxy S3 SGH-I747 with ClockworkMod Recovery installed.
  • Read this guide on how to install ClockworkMod Recovery on your Galaxy S3 SGH-I747.
• Charge your phone's battery to at least 50% to avoid installation interruption due to power loss.
• Go to Settings > Storage > Menu Key > USB Connection and select Mass Storage.
• Backup all personal data on your phone to make sure you have a copy of your personal data (e.g., contacts, SMS, MMS, Internet settings, Wi-Fi passwords, and the like) in case the procedure in this guide erases such data.
  • For backup tips, check our guides on how to sync your data to the cloud and how to create local backups of your mobile data.
• Download the following files:
  • CyanogenMod 9 ROM (get the most recent build)
  • GApps (Google Apps) package (gapps-ics-20120429-signed.zip,
    md5sum: 7c524e1e078164f681e0aa6753180b2c)

Instructions

1. Copy the two ZIP files to the root of your phone's internal SD card.
2. Boot your phone into ClockworkMod Recovery Mode:
   1. Switch off your phone.
   2. Press and hold down the Volume Up key, Home button, and Power button together until you see the Samsung logo.
   3. To navigate in ClockworkMod Recovery Mode, use the Volume buttons to navigate and the Home button to select an option.
3. If you are coming from a non-CyanogenMod 9 ROM, wipe your phone's data first:
   1. From the main menu, select the Wipe Data/Factory Reset option
   2. Confirm the action on the next screen.
   3. Wait for the data wipe to finish.
4. Go back to the main menu. Select the Install ZIP From SD Card option.
5. Select Choose ZIP From SD Card and select the ZIP file for the CyanogenMod 9 ROM.
6. Confirm the installation by selecting Yes – cm-9-20120718-NIGHTLY-d2att.zip on the screen that will follow.
7. Go back to the main menu and flash gapps-ics-20120429-signed.zip in the same manner as in steps 4 to 6.
8. Once done, go back to the main menu select Reboot System Now. The initial boot up may take up to 5 minutes.

Congratulations! You've just installed CyanogenMod 9 for the AT&T Galaxy S3 SGH-I747. Watch out for some Jelly Bean action in the coming days!