iPhone 7 Touch screen, weird problem!
 

Hi. I have iPhone 7 with weird touch screen problem. After screen replacement, touch screen is not working. But when I disconnect home button flex, it works normally. Have tried with other button and other original lcd, and even made a factory reset. Didn't helped :(

Connector is looking good and in diode mode on multimeter all pins on connector J4502 and J3801 have correct values. Checked FL3904 and its ok. I have noticed that when home button is connected, there is no PP1V8_TOUCH.

One more thing. When home button is disconnected, iPhone does not enable assistive touch so I cannot activate iPhone and therefore can't be used.

Does anyone knows what could be wrong? Please help. Thanks

hello try another flex cable for the home buuton

have tried, didn't helped.

i have same problem with iPhone 7 touch not working, i tried two screens but same problem, i checked J4502 and found that all pins have correct values except pin 18 have 250 resistance which should be around 490 this line for ( SPI_AP_TO_TOUCH_MOSI_CONN ) coming directly from the CPU to FL3904 which replaced but still same value and touch still not working, please need you guidance to fix this problem .Thanks

Connect lcd flex and home button, and check with diode mode PP1V8_TOUCH

i connected LCD and home, switched phone on and keep measured both side of FL3910 while phone booting the PP1V8_TOUCH is missing .what is that meaning .the resistance value of pin 9 while phone off with no battery is 530 with connected LCD and home .

I'm confusing what is going on phone was working fine but no speaker i opend it and cliked dock flex and speaker works but touch stopped working . i discunnctd the dock flex and changed LCD and tried with other phone housing but no luck.

Please help.

please need your help and guidance to solve this problem .

did you found the solution? I have the saaaame problem. With j3801 connected touch not work.

So no solution for this problem?

i need a help, i have a same problem please help

3d touch ic problem for me

u3801
u3801
u3801
u3801
u3801
u3801 7 plus