Tommy

here is hint my laptop was so slow ..mean too much than regular i did all kind of lots service try to clean n etc.. but i couldn't do coz so slow.. even norton scan neither, before starts format, i replaced hard driver and then works normal speed , i had extra hard driver which has win 7 already installed.. when i check my hard driver was rust n rotten some pcb board on hard disk driver,,, i cleaned with alcohole and so replaced again with original had driver , then normal working coz i did spill some juice or water on my laptop keyboard 1 years ago... now its working normal speed... hope this help

try to replace front camera flex cable.. might proximity sensor make short inside.. or flex cable anywhere.. if screen is working when u believe 100% screen was work. mine was bad lcd screen ( might be my miss handling) and camera flex i replaced it ,then its works well... (1) symtom? was logo coms on twice and LCD gone just dark , black but back light still on, replced brand new then its work ,that time ,i disconnected all other cable..like camera, home button, just only digitizer and LCD cable only.. e\works good.. now i attated camera part, same happen again.. and replaced camera part flex.. now works ok.... itune still reconize without lcd or any cable when i hook up usb on computer.. thks hope help this

you can fallow and check whtat Hassan Saeed said on above 1, disconnect the camera flash and proximity flex cable connector from main board and test it... don't forget to charge ur phone.. 2, and shoulf check all connetor on mother board by magifier,u can't check damage by ur visual.. 3, still problem?, replace lcd old one whitch is working lcd screen.. don't go DFU mode or recovery mode.. it ain't help.. bad lcd problem too bad product make making cruption on mother board flash memory.. and still no luck? u need replace motjer board flash memory.. lots money for fix u better throu it away flex cable its only less $5.. u can order on e-bay.. this for help.. thks

the problem is logig board broken its tinnny spring wire is water damaged and wire lusted and then disconnect u need micro scope and soldering system if u wanna fix this problem not easy fix by ordinary people iphone 4s and 4 and 5, most located near by bottom side on logic board.. its blue coil tinny u need hot air blower for fix this.. i fixed this prob 2 times.. more details on youtube.. u find it out i don't know.. thks

Its too hard to set it back but u must put back holder first and put pin in and spank it now i knew how can put it back.. i just failed this , now i got screwed up its so much hard to get it back