iPhone 4 GSM flickering vertical colored lines in black screen prob?

hi to all! i have a prob with my iphone 4. i opened it cause the headphone jack that i plugged-in stucked and yes i was able to remove it.its quite hard but i searched the net for some troubleshooting technique and guides on how to open the phone.but, suddenly when i put back all the screws in it, my display was gone but i knew that its still working cuz i can still hear the sounds. the screen has vertical colored lines in black screen. what i did i enabled voice-over in accessibility setting using itunes so i can still navigate my phone. the screen has no crack or never been dropped. i tried to restore it but nothing happened, same problem. i JB it myself using evasion at first because it was on 6.1.2 firmware and i did it successfully,by the way its not open line on my 1st JB cuz its carrier is sunrise w/c is from germany. but when i restored it and JB it to ios 6.1.3 using silverwind i did able to unlock it or i was able to open line it. but then, the screen still has colored lines in black screen. i can also navigate my iphone when i plugged it in to computer and use itools the updated version and click on the live desktop and yes i was able to see the screen of my phone on the computer using itools without the voice-over enabled. i would like to know if there's a way to fix this. i ve searched countless times in the internet and there's just no solution to it. i just hope its just a software issue so i can deal with it myself. but f it's a hardware then there's nothing i can do. i just dont want to spend a lot of money in replacing with a new screen and having the same prob. and that costs much. i'd rather sell it if that's the case. can someone help me please? for those having the same prob. pls share ur experience so together we can help fix this prob. thank u. i tried every possible way to fix it but nothing happened. some says install an app from cydia and run it for several hours, put ur phone in a freezer for a couple of minutes, drain the battery, exposed ur phone to direct sunlight for a couple of minutes, ensuring the screws to put it back in the right place, run a video that corrects dead pixels for hours and nothing worked. i'm so desperate to find a solution fir this.