How To Flash a Custom ROM On Your Android [SAFELY]

So you just saw a fancy custom ROM on an XDA thread and now you just can’t wait to try it on your android device. Great! But before you decide to get your hands dirty, it will certainly not hurt to get yourself a little bit familiar with the entire process of flashing.

[su_note note_color=”#ffff66″ text_color=”#000000″]Please note – This post is meant for educational purposes. Flashing a third-party ROM always carries a risk of damaging your android device (if you do something wrong). I’m writing this article based upon my own personal experiences of trying various ROMs on my android device. What worked fine for me, may not work for you. I shall not be held responsible for any damages that may occur to your device. Do your research well and proceed at your own risk. [/su_note]

1. Take a ‘nandroid backup’ of your current ROM

A full nandroid backup of your current ROM can save you from serious troubles if things unfortunately start getting south with your fancy custom ROM. Always be aware that most of the custom ROMs generally do have some bugs in them. They aren’t as stable and completely bug free as your stock ROM. In one of the worst cases of custom ROM failures , I still remember how scared I got when a custom ROM failed to boot beyond its boot screen on my android device. Thanks to my nandroid backup, I immediately restored the stock ROM back and my phone was saved 🙂
So my sincere advice is to always be prepared for the worst and have a full nandroid backup of your working ROM ready before flashing any other ROM on your device. Don’t know how to take a nandroid backup? Don’t worry, I will show you how:

• Install ROM Manager Premium on your device (Don’t want to spend? Use 4shared to find the apk)
• Open ROM manager and scroll down to find an option to take ‘backup of current ROM’.

Rename the backup file name or leave it as it is. Then the app will boot your phone into recovery mode and the backup process will be started in no time. On successful backup, reboot your device from recovery. That’s it.

• To see your backup file, launch any file explorer app on your device and navigate to SD Card > clockworkmod > backup.

2. Backup your contacts and messages

Contacts and messages are stored on the internal storage of your Android device. So they will be erased completely right after the moment you execute the ‘wipe data’ option in the ‘recovery’ during the flashing process. So it’s very important that you backup your contacts and messages before replacing your ROM with a custom one.
Rest, be assured that your SD card’s content will remain safe since flashing works only on the internal storage 🙂

3. Check the compatibility

Pretty obvious! Ensure that the ROM you are downloading is exclusively cooked for the model of your device. For example,  if you are using a Nexus 5, stay away from custom ROMs developed for Nexus 6. Just stick to your model.

4. Read the reviews

Finally, go through all the reviews of the ROM you are downloading. Pay attention to what the people are saying about it. This will give you a fair idea of what’s expected to work and what isn’t.

5. How to flash a custom ROM?

Now that you have finally decided to flash the ROM, make sure that you do it the right way. The downloaded package will be there in .zip format. You have to transfer it to your phone’s SD card by connecting it via USB cable (don’t make any folder, just transfer it to the root directory of your SD card). Now disconnect the USB connection and switch your phone off. Boot into the bootloader by pressing the volume down and power button simultaneously. From there choose to boot into recovery.
The actual flashing process will start from here. In the recovery, follow the following steps sequentially to flash your custom ROM:

[su_note note_color=”#ffff66″ text_color=”#000000″]

1. Wipe data/factory reset 
2. Wipe cache partition
3. Choose zip from SD card
4. Select the downloaded package and execute
5. After the flashing is complete, reboot from recovery!

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Note: Use volume up/down button to navigate-through/select and power button to execute the options in the recovery.

Refer these screenshots:

That’s it. Enjoy your new ROM safely 🙂