Glass only replacement for the Samsung Galaxy S4 is an advanced level repair.
This requires practice and there is a very good chance that you will fail the first time that you attempt to remove the old lens. Using the proper equipment will minimize this risk but the AMOLED on an S4 is very heat and pressure sensitive. Too much force will cause it to crack. Too much heat will burn the display. Too little heat will also cause damage when removing the old lens. Proceed at your own risk. If your Galaxy has a broken AMOLED proceed to this page.
The glass lens of a Galaxy series phone such as the S4 can be replaced independently provided that the digitizer is still fully functional. Unlike traditional touchscreen phones the Galaxy series which feature a Super AMOLED have a digitizer mounted directly to the display rather than being attached to the outer lens. Because of this it is possible to pry between the glass and the digitizer while preserving the AMOLED and the touchscreens functionality. In order to remove the old glass however we must heat the surface to a specific temperature. This will make the glue pliable enough for us to get between the glass and digitizer with a thin and flexible pry tool. For all practical purposes a playing card works as well as anything else and can be purchased at a variety of retail stores. Once we reach the correct temperature, about 110 C for the S4, we can then begin to carefully pry between the glass and the edge of the phones frame. We start out using something relatively strong like a razor blade or box cutter since getting under the glass initially can be a bit difficult. Once we have begun to pry them apart though we will immediately switch over to something more flexible. Playing cards are also coated with a wax like substance which allows them to slide between the two surfaces with little friction. You may use a several cards during this process as the corners tend to wear down during this step of the process.
This is not recommended for amateurs as damaging the AMOLED is a good possibility when any of the above criteria are not met.
In the video below we demonstrate the steps required to remove and replace the glass lens of a Samsung Galaxy S4. Using a heating plate we raise the surface temperature to 120 degrees C.
The tools shown in the video are listed below:
UV Ultra Violet Blacklight 51 LED Flashlight Torch Lamp
After removing the old lens we will thoroughly clean the surface of the AMOLED. Any residual glue or dust left behind will cause bubbles to form between the lens and digitizer. These will not always affect your touchscreens performance but they are unsightly. Fortunately when one of these bubbles does end up being visible they don’t look quite so bad when the display is turned on. Still, we want to take whatever steps are necessary to prevent them from forming in the first place. Canned air, a lens cleaning cloth and a lot of patience are the best tools for this job. Once we cure the LOCA glue it is very difficult to remove the lens so do your best to get this right the first time. Working in a dust free environment is very helpful if you have that option.
Once the digitizer has been cleaned we will apply the LOCA glue. This glue is specially formulated for bonding transparent surfaces and is itself transparent allowing us to see the display without any distortion once it has cured. This is accomplished by placing the glued surface under an ultraviolet lamp. Remember that the glass side must be facing up in order to allow the UV light to affect the glue. This process only take about five to ten minutes. You will need to make sure that the LOCA glue covers the entire surface but be careful no to overdo it as sometimes it can leak out of the desired area and into other parts of the phone. In particular the home button, earpiece, and proximity sensor are at risk as they can be seriously affected by exposure to this glue.
After the lens has been replaced it will be slightly more difficult to replace should the phone become damaged again. LOCA glue applied in this manner is particularly strong. This is a good thing as it will keep the lens from lifting off of the phone but of course the down side is that someday you may want to do exactly that. We recommend using a heavy duty case for your Galaxy S4 to protect it from future mishaps but this comes with the price of making your phone bulkier.