CyanogenMod 9 is out from a while, the ROM being available for numerous smartphones already. Starting from now, this can be applied for the Samsung Galaxy S2 HD LTE SGH-I757M handsets too, as thanks to those of xda-developers, the CM9 firmware can be safely installed on the up-mentioned device. But in order to update your phone with a custom ROM you will have to follow this guide, because if you are not using a step by step guide you can end up in bricking your beloved SGS2 HD LTE.
Take note that the present firmware isn’t coming from Samsung, so it has nothing to do with the already mentioned company. Unfortunately, by flashing the CM 9 ROM you will lose the Galaxy S2 warranty due to the changes that will take place on the phone’s internal system. You can easily regain the warranty by applying an official update or by getting the stock ROM (a downgrade might be required). In this way you will be able to relock the bootloader and reinstall the default restrictions. Don’t worry though as bad things can happen rarely and only if you are trying to complete the procedure by yourselves without consulting a tutorial.
Furthermore, you will not be able to update the SGS2 with CM9 if you don’t have a rooted Android powered device. So, go and gain root access first. Also you must install a custom recovery image into the system; the tool will offer the possibility of flashing the software file from the SD card. You can see how to do this by checking our previous step by step guides. You can then return here and resume the operation. Without these tasks completed you can’t take advantage of CM9 and you can’t update your smartphone.
CyanogenMod is one of the most used ROMs, the software being based and developed relying on the Android platform. There are more versions of CM available depending on the version of the Android OS. So, CyanogenMod 9 will update your Galaxy S2 HD LTE with Ice Cream Sandwich and with its features. Beside the classic features, the firmware will also bring its own capabilities, improving the default OS that runs on your handset. Usually, a custom ROM comes with features not found in the default version of the Android firmware and is used for powering the performances of a smartphone.
The S2 that runs CM9 is gaining more speed, uses the RAM memory better than before, has an improved battery life and offers an upgraded ICS experience. The looks are different from the default ones too, the CM team developing a personalized theme, background image, side bar, and so on. As you can see, by flashing this custom ROM on your device, you will be able to take full advantage of its capabilities, not to mention that the internal system is already unchained from the annoying factory restrictions; and who doesn’t want that?
As a final recommendation, you should backup the data before starting the proper guide. Your personal data will be erased as you will have to do a full wipe somewhere during the steps. A backup can be completed in different ways, showing it is not our purpose now. But, you can use a custom recovery image for saving several stuffs, or you can download free distributed backup apps from Google Play. If you want more details about this subject you can search for the same through our backup step by step guides.
We mustn’t forget the pre requisites though as this represent the most relevant part of this tutorial. You will need to have access to a Windows running computer and to the phone’s USB cable. On both, the PC and S2 HD LTE you should uninstall the antivirus programs. Also, the handset must be fully charged, or it should have 60% battery power remain. On the smartphone go and enable the USB debugging option. It’s important to have a rooted device with a custom recovery image pre-installed.
And with that we are done. You can now head to the final section of this guide.
How to Install CyanogenMod 9 on Galaxy S2 HD LTE SGH-I757M
- Download the CM9 file from here and place it to your computer.
- Download Google apps from here.
- Connect your phone with the computer.
- Copy the files downloaded in step 1 and 2 from the PC to your phone’s SD card.
- Disconnect the handset (remove its USB cable).
- Reboot and try to enter in recovery mode: press and hold on Volume Up and Volume Down while powering on.
- From recovery mode select to perform a full wipe: “wipe data factory reset” and “wipe cache partition”.
- Return to the recovery menu.
- Select “install zip from sd card” and “choose zip from sd card”; pick the CM9 file first and then do the same for the Google apps.
- Click on “Yes”.
- Wait until the process ends.
- In the end, from the recovery menu select “+++go back+++” and “reboot system now”.
- The ROM is set on GSM (3G/HSPA). For 4G connection, go to: “System Settings –> More –> Mobile Networks –> Network Mode –> LTE/GSM”.
Congratulations, you have finally managed to install the CyanogenMod 9 custom ROM on your Samsung Galaxy S2 HD LTE SGH-I757M smartphone. Your handset is now updated with Ice Cream Sandwich flavor, so test the firmware and see how it works. If there are bugs in the system don’t worry as the CM team is working to resolve them. Stay close for further updates and don’t hesitate in using our Android related tips.