SlimLP Alpha 1 ROM for Galaxy S4 LTE (GT-I9505)
How to update Galaxy S4 LTE (GT-I9505) to Android 5.1.1 via SlimLP custom ROM XDA Developers

Galaxy S4 LTE (GT-I9505) users can now enjoy the latest Lollipop experience on their ageing smartphone, with due credit to the industrious Slim ROM, SlimSaber and JDCTeam developers for releasing the Android 5.1.1 SlimLP ROM that brings a fast and stable Lollipop experience in an extremely lightweight package.

The SlimLP ROM brings a blend of the best features extracted from top custom ROM releases such as CyanogenMod, SlimROMs and SlimSaber ROMs for a faster and smoother performance.

The ROM is built entirely out of SlimLP source, which uses optimisation methods found in SlimSaber GitHub along with Uber Toolchain support, while the kernel combines alucard and stock versions to deliver the best possible experience to the user.

This SlimLP ROM is reportedly compatible with all Galaxy S4 models running Snapdragon 600. The supported models are listed below:

  • GT-I9505
  • GT-I9505G
  • GT-I9507
  • GT-I9508
  • Any SCH-I545
  • Any SCH-R970
  • Any SGH-I337
  • Any SGH-M919
  • Any SPH-L720

Interested users can go ahead and install the latest Android 5.1.1 Lollipop custom firmware on their smartphone via SlimLP ROM using the step-by-step guide provided below.

IBTimes UK reminds readers that it will not be held liable for any damage to their device during or after the custom ROM installation. Users are advised to proceed at their own risk.


  • The instructions given in this guide are meant for international variants of Galaxy S4 (GT-I9505) only. Verify device model number by navigating to Settings > About Phone.
  • Ensure the phone has at least 80% battery charge to prevent unexpected device shutdown (due to battery drain) while installing the ROM.
  • Back up data and settings using a recommended custom recovery tool, like ClockworkMod (CWM) or TWRP, as it creates a complete image of the existing phone setup. In Recovery, choose Backup and Restore and tap Backup.
  • Verify correct USB drivers for the phone are installed on the computer (download Galaxy S4 USB drivers).
  • Enable USB Debugging mode via Settings > Developer Options (if running Android 4.0 or above) or Settings > Applications > Development (if running Android 2.3 or earlier).
  • Ensure that the device is rooted with CWM recovery installed and its bootloader is unlocked.

Downloads Required

Android 5.1.1 SlimLP ROM (with stock aka CyanogenMod kernel and Uber Toolchain)

Android 5.1.1 SlimLP ROM (with Alucard kernel)

Google Apps or Slim Gapps

Steps to Install Android 5.1.1 SlimLP ROM on Galaxy S4 I9505

Step 1 - Download Android 5.1.1 SlimLP custom ROM for Galaxy S4 on the computer.

Step 2 - Connect and mount the phone's USB mass storage on computer with the USB cable.

Step 3 - Copy the downloaded SlimLP ROM zip file to the root folder on the phone's SD card.

Step 4 - Power off the phone and disconnect its USB cable from computer.

Step 5 - Boot the device into Recovery Mode by pressing Volume up, Home and Power buttons on your phone.

Step 6 - Once the phone enters into CWM Recovery, perform a full data wipe task by clicking Wipe Data/Factory Reset. Use the Volume keys to navigate between options and the Power button to select an option in the Recovery Mode.

Step 7 - Then, perform Wipe Cache Partition and wait until the process completes.

Step 8 - Perform Wipe Dalvik Cache as well. To do this, go to the 'advanced' option and then click Wipe Dalvik Cache. This will help in preventing boot loop issues or any boot ROM related errors during firmware installation.

Step 9 - Return to the main recovery menu and choose Install Zip from SD card.

Step 10 - Click Choose Zip from SD card. Use volume keys to navigate to the SlimLP ROM zip file that you copied earlier to your phone's SD card and choose it by tapping the Power button. Confirm the ROM installation on the next screen and the installation process will begin.

Note: Repeat Step 9 and Step 10 to install Google Apps (Gapps) as well.

Step 11 - Once both the Gapps and ROM are installed, go to "+++++Go Back+++++" and select Reboot System Now in the Recovery menu.

The phone will now reboot and the first boot may take about five minutes to complete. So, please be patient.

Your Galaxy S4 GT-I9505 is now running the latest Android 5.1.1 Lollipop via SlimLP custom ROM. Go to Settings > About phone to verify the firmware version installed.

[Source: XDA]