The 1520 is a bit different than most phone screens I have repaired ,, I searched and didn't find video for a digitizer replacement procedure (glass front top and bottom glass on the 1520) , I was able to buy one pretty cheap so I decided I had nothing to lose and everything to gain by giving it a try ,,I contacted several phone repair shops to get some consulting , no one was able or willing give advice on how to remove it ...
Here is what worked for me , lots of vids out there to remove the back so I wont go into details on that ..
I made a fixture on a board to hold the phone with sheet metal screws vacuum hose around them would be good too ( very careful to not get it too tight ) you have to work out the details , the next one I do I will make a youtube video ,, ( I would have done a video but I had no idea how I was going to do it )
The phone actually has a 2 glass layer digitizer thicker glass on the outside and a very thin glass against the LCD
I had a friend with a heat gun and a laser temp gun sensor making sure the temp didn't go over 80 c as I had a fine phone wire to separate the top glass from the bottom glass of the digitizer ( the fine phone repair wire available on the ebay or amazon )
might be better if you can go directly to the bottom glass but for this first op (no Idea if this is possible ) I took the top glass off first and then the glue .
(not an awefull task but care must be taken not to break the LCD of course )
the bottom glass next to the digitizer is a very difficult task , the glue on the one I have was not that tuff but very sticky ... the big problem is the bottom glass is so thin that you cant use a phone wire. the glass keeps breaking off ,, so I did it the hard way with a razor as it broke away as I got the razor under it .. if you can find a brass razor would be awesome ..unless you went right to the bottom layer but I think maybe the heat transfer may not work as well if you don't take one layer off at a time .. would love to hear other success stories of course.
very painstaking task as it took a long time for me
I used nail polish remover to remove the glue residue ,, it worked for me , maybe some way better chemical but I have an idea the LCD is very fragile so I kept pressure to a minimum ..
The wire with chip on it that connects the digitalizer to the logic board just pulls out of the connector but the chip on the wire is glued to the frame of the phone .. to remove that connection you must remove the Logic board .. (videos out on youtube to remove ),, the battery does not have to be removed ..
I am guessing its not cost effective for a phone repair shop to attempt this cause it too me several hours of careful work and would be very easy to make a mistake .. would love to hear about a procedure that is easier ...
and would love to hear other success stories too ..
This is home style repair that worked for me