You can repair your broken touch screen by yourself which is pretty simple, easier and its cheaper than you think. All phones have their different configurations, but many uses a touch-sensing device is known as the digitizer or LCD/OLED display. The digitizer guards the main display screen, which is why it breaks first instead of the display. A broken display normally shows the rainbow effects and does not work in some sections.
Guidelines for how to fix a broken touch screen:-
Before starting the tutorial you are going to need a pry tool, jeweler screwdriver and a set of star shaped (torx) drivers sized 4 to 7. Here we are going to show you how to replace the digitizer of HTC desire S.
Clean the work place and light it well because you are going to be deal with small screws that you should place in order, as you remove them. Remove the cover, battery, SIM and SD cards from the phone safely.
Remove the four size 5 Torx screws from the base of HTC Desire S around the battery cover. If you are in doubt then take photograph of your device as you are continuing further.
By using pry tool, you can extract the cover from the top of the camera. For better result start from a corner and when it is done fully take off the cover from the body. If any visible connections are there then un clipped it and remove two more screws using size 5 torx. Now carefully push the main device and take out from the metal cheeses screen.
Take out a couple of more screw using size 5 torx and it will release the plastic bracket, take it away and keep safely. In this point, we are separating the display elements from the motherboard. Find the two ribbon cables, which are the connections of digitizer and display. Using the pry tool remove the tape and pick up the white locking element. Remove the connections with the help of small crew drivers.
Now display is depart from the motherboard. In many cases, the display is fixed with motherboard. For separating the display use the pry tool and remove it slowly and carefully. This is the hardest part and it will take long time.
A substance binds the digitizer to the display chesses. It needs to be heated for separating the digitizer from the display. Use a hair dryer to heat the substance otherwise too much heat may destroy the display.
Start from the broken sections Just check the sticky substance using the pry tool and reheat until it starts coming away automatically. Move on to next small sections and repeat the same. After some time, take away the digitizer from the screen. If the adhesive gasket is damaged then you have to replace with 1mm or 2mm adhesive tape designed for phones. If any area of the digitizer touches, with the display screen, it will short and it will give crazy signals.
Remove the protective film, feed the new digitizers ribbon through the lower small hole carefully from the base, and reverse the above process to rebuild your phone.
At last press the power button, if it all has gone well then your phone will come back to life again.