Replacing the broken glass on my samsung galaxy s4. I used the heat gun and believe I put it too close to the screen. Thus, discoloring the screen and forcing me to buy a $100 new screen/digitizer/lcd.
Using the heat gun for the recommended time, I still managed to discolor my phone screen because the gun was too close to the device. I was happy because I managed to finally have a utility to caramelize the sugar on top of the Crème brûlée.
Do not use the heat gun too close to the device. Use low heat, don't overheat, maintain a good 5 inch distance above the device.