Fix for 4G LTE option missing in Samsung Galaxy S4 i9505

UPDATE (26th Apr, 2014) :- It is happy to inform you all the fellow Sri Lankans that this issue has been fixed for Dialog & Mobitel users through the 4.4.2 KitKat update. So all you have to do is update and the LTE mode will be available.

For the rest of the people who are still unable to get LTE working on i9505 devices around the world, please follow the guide.

Hey guys, first of all this post is only for the i9505 variant of the Samsung Galaxy S4. If you have an i9500, please do not continue because this is not regarding this particular model, which doesn't have 4G to begin with. So if you have a Samsung Galaxy S4 i9505, and if you are finding the LTE option missing in your network modes (if you don't get 4G signals), this is for you.

(Settings / More networks / Mobile networks / Network mode)

As I've mentioned above, if you don't get the LTE/GSM/WCDMA option in your network mode just like the above picture shows, don't worry, there is a way to get this back and no it is not something to do with your phone having any factory fault or anything like that. This is simply due to the issue that certain network carriers in some countries are not recognized by the device as networks that have 4G LTE.

Before we talk about how we fix the issue, you have to make sure that you already have obtained a U-SIM (4G Enabled sim 64k or 128k) and activated the 4G service from your service provider. To use LTE you have to get that special sim. if you are by any chance trying to enable 4G without getting the proper sim, you most certainly will not get 4G signals or the option itself. So make sure you have the proper SIM before doing anything else.

Now to the real issue, even though you get the U-SIM, there is a chance you won't get the LTE option. Not everyone experiences this, but unfortunately some do. This happens with certain service providers as I mentioned before. I for an instance use Dialog GSM (Sri Lanka) and experienced the same problem.

There are two methods, one very easy, and the other one is a bit complex. Method 1 is only for devices with the firmware 4.1.2 or 4.2.2 (below 4.3 / 4.4.2) version.

Here goes.

Method 1:

First make sure what firmware your device is currently on. (Settings / More / About device). Under android version, if your firmware is below 4.3 / 4.4.2 (eg: 4.1.2 or 4.2.2)  you are in luck, as in the procedure is simple as cake. Just go to Google Play and download 'Viaero 4G toggle'. When you open the app, select phone information and select LTE/WCDMA option from the 'set preferred network type' list. Voila, you will get LTE signals.

Method 2:

So by any chance if you had your i9505 updated to the latest version which is 4.4.2 or 4.3, unfortunately the 4G app will not work. But there is still a way to turn it on without the app. But as already told, a bit complicated than the method 1. But those computer/phone geniuses will find it very easy because it's not basically rocket science, just a matter of rooting the phone. By following this method, the issue can be completely fixed, meaning the option in the network mode will be restored, the only cost is having to root the device.

There are some risks and downsides involved by rooting the phone, so make sure you read the article in the following link top to bottom without continuing. And it is totally up to you if you decide to change your mind.

Here is the link to the article for rooting your i9505 device (4.3 / 4.4.2 firmware only) :

http://true-android.blogspot.com/2013/11/root-i9505xxuemkf-galaxy-s4-gt-i9505.html

After you have rooted the device completely, go to Google Play and install 'ES file explorer'. Open the app, and press the menu key on the device and you will get a panel to your left on the screen. Scroll down and enable Rootexplorer (you will ask to grant permission by the SuperSU app since you have rooted, so give permission). Now use the search function and find the file with this EXACT name 'persist.radio.lteon' and delete it. Please make sure you are deleting this exact file. Don't delete anything else and end up bricking your device. After deleting restart the phone and that's it! You will have the LTE/WCDMA/GSM option in the network mode once you are booted and you will receive 4G signals if you are in an area with LTE coverage.

That about it. Hope all of the people out there with i9505s in hands with this issue can use this guide to fix the problem with no hassle.

Note: I do not take any responsibility if by any chance your device gets bricked, use these methods at your own risk!

Cheers!