Post originale di: kcthole ,
I originally posted this as an answer for a galaxy tab s glass replacement procedure, but it is relative to most AMOLED glass repairs, so I'm copying it to here as well (I apologize for the length, but I wanted to be as thorough as I could be)... I am an experienced cell and tablet repair tech, and have some insight. I too cracked my tab s 8.4 glass several months ago. I figured that like all AMOLED (as far as I know at least) screens in Samsung devices, the glass was bonded to the LED with LOCA. I've repaired the glass on hundreds of Galaxy S3/S4/S5 during the last 3 years, and the way I do it takes about 10-20 minutes (depending on how much the glass is actually shattered). Granted, an 8.4 or 10.1 inch screen is at least 3 times the surface area of any of Samsung's smartphone lineup, so it should take more time. That being said, there is a way to replace the glass of any AMOLED screen if you have the right tools. As a disclaimer, I should warn anyone before trying to repair any glass on an AMOLED screen. You should be aware that you will require both LOCA AND a UV curing "oven" (<-- that's what I call it) to correctly repair these screens. Most of you probably know this but for those that don't, LOCA stands for "Liquid Optically Clear Adhesive" and is an absolute necessity for replacing cracked glass on most if not all AMOLED screens. Using regular adhesive around the edges of the glass replacement will result in an ugly and dysfunctional touch screen, and will eventually fall off and/or fail. Even if you purchase the correct LOCA, it is useless without having a UV oven to cure it. That being said, if you can have the necessary tools at your disposal, the following is how I repair AMOLED screens to an almost new condition. So, as I've said, you will require some UV cured LOCA, and a way to cure that LOCA as well. Also, you will need a way to carefully heat up the screen during the repair procedure. Personally, I use a temperature controlled heat gun. I read that some of you use a temp controlled hot plate which can work I suppose, but I strongly suggest using a heat gun with the ability to set the temperature. The ability of a heat gun to heat up specific areas of the glass on demand makes the method I use much easier. You will also need a very thin pry tool (I use a very sharp and very thin razor blade), a pair of gloves that will protect you from heat, and most importantly... a roll of thin steel or kevlar wire. I'm not sure of the gauge I use, but it's as thin as strong fishing line. Oh, and obviously, you will need a replacement glass panel for your particular device. Alrighty... Now, I'll explain the procedure. To begin, I turn the heat gun up to 300 degrees C. A lot of you will think that is high, and you're right.. but I like having it up high so the screen heats up fast. DISCLAIMER: IT IS VERY IMPORTANT TO NEVER HOLD YOUR HEAT GUN OVER ANY PARTICULAR PLACE ON THE SCREEN FOR MORE THAN A SECOND OR TWO AT THIS TEMPERATURE!! It's very easy to destroy the LCD even through the glass relatively quickly, and if you see any unusual discoloring behind the glass while heating, just give up. The LCD will work, but there will be no way to ever buff out that blemish, and you might as well just replace the entire screen assembly if it happens. Also, always look up information about the hardware configuration of the screen you're working on. AMOLED screens have the touch screen integrated in the display itself and have both a display flex cable as well as a digitizer flex cable. This is important because you need to be weary of cutting or damaging the digi flex while you start to pry the glass up. For instance, the Galaxy S4 digi flex is in the upper left corner of the screen. Anyway, start to evenly heat up the very top of the screen where the Samsung logo is. After a few seconds of heating, use your razor (or whatever pry tool you decided on) to go underneath the glass and start to pry it up. It may be important to note at this point that LOCA is only used where the glass is transparent, while normal adhesive is used on the top and bottom parts (the colored portions. Make sure to use the heat gun to keep the area you're prying up warm enough to loosen the adhesive underneath. Continue prying around the top of the screen, until you've separated the adhesive in the top portion of the device only. Do NOT accidentally puncture the actual display. Once the glass on the upper part of the device has been sufficiently separated from the frame/screen, start to lightly and evenly heat up the glass of the upper area of the display, lightly prying up on the glass at the very top of the device. You should notice the glass starting to peel away from the display, causing the screen to look like it has blurry gel under it. At this point, put your gloves on, and pull out a piece of steel wire about 18 inches long. wrap each end around a finger of both hands, and start to thread the wire in between the glass that you just pryed up and the screen/frame of the device. Now comes the slightly tricky part. You need to start evenly heating up the screen below the wire, and when its pretty warm to the touch, start to pull the wire down the screen underneath the glass. The heating weakens the LOCA, and we're basically using the wire like a cheese cutter, warming the LOCA then slowly pulling the wire down. You will have to repeatedly heat up the glass down below the wire several times, heating, then pulling, then heating, then pulling, until finally you reach the bottom of the screen and are able to start prying the glass left at the bottom from the regular adhesive just like you did at the top. It is not as easy as I made it sound, and it is VERY important that you take your time and not force anything. When the glass is severely shattered, it's common for the wire to get snagged on the edge of a shard or crack in the glass. If this happens, use your razor to gently pry and lift the edge of the screen where the wire got snagged, making sure that again, THE SCREEN IS WARM where you pry! If all goes well, the glass should eventually come off leaving a screen covered in a now cloudy substance that feels like rubber to the touch. This is the LOCA. I read in someones answer above that they used a tool to peel the LOCA away. I DO NOT RECOMMEND THIS!! The LCD is easily punctured and damaged so using a tool to peel the LOCA away is dangerous. All you need to do is use your fingers :). You will find areas of the screen where the actual LCD is visible because the LOCA was pulled away by the wire. With a finger (I use my thumb), pull down with some pressure on the exposed area of LCD and start to peel the LOCA down slowly. If done correctly, the LOCA will be easily taken off after a good bit of attention. It's tedious, but once you've finished, you'll have a screen that's mostly LOCA free. At this point, I use a little googone with a microfiber cloth to scrub away anything that may be on the screen. Don't worry about making the screen spotless. A few blotches of LOCA left is perfectly acceptable and will disappear when you put the new LOCA on for the replacement glass. After the screen is sufficiently clean, you should remove the old adhesive on the top and bottom of the display area and replace it with some new double sided, typical adhesive. There's a bunch of places online that sell precut adhesive for almost any particular device which makes it a lot easier to apply and covers the maximum area of the screen without blocking any sensors/buttons/etc. Just to give some advice, you should cut several thin slices of adhesive (about 1mm thin) that's the length of the width of your devices screen. I use it to put at the very top and bottom borders of where the actual LCD meets the area with the precut adhesive you previously applied, and lay it the entire width of the LCD, edge to edge. Put at least three layers of the same thinly sliced adhesive on top of each other. This is used as a kind of barrier to protect the sensors at the top and home button/capacitive buttons at the bottom from being covered with LOCA prior to it curing. DON'T SKIP THIS STEP!! If you do, say goodbye to your front camera and a responsive home button. Now, I'm gonna try to explain this as best I can, but I understand that a video is probably necessary to fully explain. Grab your LOCA. Applying to LOCA correctly is tricky, because it's easy to put way too much, and also important to make sure the entire LCD will be covered with it once you start putting on the new glass. I start towards the upper part of the LCD about 3/4 of an inch from the top edge of it, and make a V. Try to keep the line of LOCA around a half cm in width as you apply it, slowly making a V. Then, from the bottom of the "V", make a line going down about an inch or so long, followed by finally, another upside-down V at the bottom. Keep the top of the V's at least 3/4s of an inch or so away from the top and bottom of the device. Now you're ready to start putting the new glass on. Make sure to have your UV light source on and ready. Start laying the glass down very gently, starting from the top of the device. Push the top of the glass into the precut adhesive you applied earlier, and let the glass start to fall on top of the LOCA. You will see the LOCA start to spread out over the LCD, and may see a couple of air bubbles. This is ok. While keeping firm pressure on the upper portion of the glass, allow the glass to go down far enough so that 2/3rds of the display underneath is coated in LOCA. It's important to keep a firm pressure on the top portion of the glass. When the LOCA has covered most of the LCD, you'll start to have some of it overflow out the sides of the device/glass. This is expected and perfectly fine. Anyway, keeping the pressure (if pressure is released, the LOCA will recede from the edges allowing air pockets to come back), start holding the device so that the upper portion (which should be down in it's final permanent position) under the UV source, double checking that all air bubbles have been pushed out through the sides of the device. Don't let the bottom portion under the UV yet or it will start to cure with out being fully seated to the display. Hold the upper portion under the UV for about 2 to 3 minutes. This allows the LOCA to cure just enough to hold it's own for the time being. After a few minutes, check the status by releasing some pressure from the upper portion. If you don't see any air pockets forming in the upper corners after a several seconds, the LOCA has started to cure. I like to be safe and follow up by curing the top portion for another few minutes. It's possible for the LOCA to trick you and if it is only cured a little, it will form air pockets very slowly. So, after making sure the top is bonded, continue to push the glass down until the final portion of the LCD is covered, and repeat the process for the bottom portion of the device, firmly applying pressure on the glass until the LOCA can hold. When both top and bottom are cured enough to hold, put the entire device under the UV light. I keep it in there for 30-40 minutes to be safe, but I'm assuming that the timing necessary really depends on the wavelength and wattage of whatever UV source you're curing with. After 30-40 minutes, pull the device out. There will probably be cured and oily LOCA all over the device. It should peel off, and you can use some goo gone or whatever to clean up any mess. So, I just realized how long this answer has become lol, and I'm thinking that this sort of procedure is definitely best learned by watching an experience tech do it in a video, so my apologies if this was horribly written and way too long. The entire repair should take about an hour and a half with a small device and I'm guessing 2-3+ hours in a device the size of a tab S. If anyone is interested in me making a video of this type of repair (maybe even my tab S if I can find the replacement glass by itself somewhere!), let me know. I can't even find a tutorial on this repair on youtube, which is crazy, so I'm more than happy to make one myself. I hope I didn't completely waste my time with this and that at least a LITTLE of the information I shared helped someone!