Touch screen problems HELP
So when i bought my Z1 it was on 4.2.2 firmware. Then i updated it to 4.3 and i never had any single problem with it, so no bugs at all. At that time there were a lot of people complaining about touch screen problems but i really never faced any.
Then 4.4.2 came, and problems with it as well. First of all battery drain, my battery was 40% wrose then with 4.3, and i started facing some touch screen problems. Usually after i enable my 3g and start surfing the net touch goes nuts and uncontroled. Also when i was typing usually only left side of my screen was buggy, for example when i type letter A it is shown as D or S or even F, and sometimes it's stop working completely, i mean only very left side of my screen.
Couldn't resist anymore so i decided to downgradd to 4.3 .290 (coz it was wroking so perfectly and i never moved to .136 coz i head there are some problems). I did that with FlashTool and i thought everything will be as before and i will be happy again. But guess what? Touch screen problems started popping! Hmm i thought what now? So i decided to upgrade to .136 as it was offered with a hope that it will fix issues. But ofc nothing happend and i am in a problem.
I even found how i can produce these touch screen problems. I turn on my 3g and start a game Clash of Clans and after few mins my phone goes crazy. Then i go in "Sketch" program and i drow a straight lines from the top of the screen to the bottom and "lines" are not lines at all, it's crazy.
So i would like to try to repair my softeare with Sony PCC but it's not possible coz there is a new software update (4.4.2) and i wont update that.
What should i do in order to get rid of this problem, im pretty sure it's software related. How can i repair it? I should fash with flashtool again?