Screen faded to black. Now iPhone won't turn On but detected in DFU

So I went to download google drive from App store. and the download got failed so I press the re try option and screen of phone started to fade out with vertical purple lines going from right to left. Then after a few moment the screen turned black completely. I plugged it into a charger and I could hear the charging sound. but after sometime the phone become totally unresponsive… No charging sound, vibration or anything else. It is only detected in itunes in DFU mode wehen I hold power button + home button for 10 seconds whent plugged in PC. I restored its formware 3 times with itunes and it went successful but just after Itunes said “ software restore is successful wait for your phone to boot up” my phone does not boot up. I shown it to local repair shop they tried another display in it but they said that its display is Ok. It got damaged IC. Now my question is which IC is damaged provided that it is recognized in DFU mode by itunes but won’t boot up?? One more thing to add is that I had used samsung 2 A charger adapter to charger it before this incident happened.

Edit: One more thing I would like to add is that when Resotre its software through itunes in recovery mode the phone get a bit hot in the area just below the front call speaker.