iPhone 7 Touch screen, weird problem! - GSM-Forum

esko1 · 06-13-2017, 21:27

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

vinse · 06-13-2017, 22:14

hello try another flex cable for the home buuton

esko1 · 06-14-2017, 16:02

Quote:

Originally Posted by vinse

hello try another flex cable for the home buuton

have tried, didn't helped.

Manarshop · 03-13-2018, 08:54

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

ninos22 · 03-13-2018, 19:42

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

Manarshop · 03-14-2018, 17:41

Quote:

Originally Posted by ninos22

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.

Manarshop · 03-19-2018, 23:12

please need your help and guidance to solve this problem .

pedritu1981 · 08-02-2018, 15:47

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

esko1 · 08-22-2018, 21:21

So no solution for this problem?

ozer44 · 11-30-2019, 20:16

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

leham · 12-06-2019, 09:50

3d touch ic problem for me

leham · 12-06-2019, 10:00

u3801
u3801
u3801
u3801
u3801
u3801 7 plus

06-13-2017, 21:27	#1 (permalink)
esko1 Insane Poster Join Date: Oct 2005 Posts: 64 Member: 193584 Status: Offline Thanks Meter: 8	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

06-13-2017, 22:14	#2 (permalink)
vinse Freak Poster Join Date: Jan 2014 Posts: 258 Member: 2106911 Status: Offline Thanks Meter: 67	hello try another flex cable for the home buuton

03-13-2018, 08:54	#4 (permalink)
Manarshop Registered User Join Date: Sep 2016 Posts: 30 Member: 2625122 Status: Offline Thanks Meter: 23	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

03-13-2018, 19:42	#5 (permalink)
ninos22 Freak Poster Join Date: Mar 2013 Location: Greece Age: 35 Posts: 425 Member: 1903358 Status: Offline Thanks Meter: 146	Connect lcd flex and home button, and check with diode mode PP1V8_TOUCH

03-19-2018, 23:12	#7 (permalink)
Manarshop Registered User Join Date: Sep 2016 Posts: 30 Member: 2625122 Status: Offline Thanks Meter: 23	please need your help and guidance to solve this problem .

08-02-2018, 15:47	#8 (permalink)
pedritu1981 Junior Member Join Date: Apr 2009 Posts: 5 Member: 1005873 Status: Offline Thanks Meter: 0	did you found the solution? I have the saaaame problem. With j3801 connected touch not work.

08-22-2018, 21:21	#9 (permalink)
esko1 Insane Poster Join Date: Oct 2005 Posts: 64 Member: 193584 Status: Offline Thanks Meter: 8	So no solution for this problem?

11-30-2019, 20:16	#10 (permalink)
ozer44 Insane Poster Join Date: Jul 2005 Location: Turkey Age: 45 Posts: 75 Member: 158930 Status: Offline Thanks Meter: 4	i need a help, i have a same problem please help

12-06-2019, 09:50	#11 (permalink)
leham Junior Member Join Date: Feb 2016 Posts: 28 Member: 2533922 Status: Offline Thanks Meter: 8	3d touch ic problem for me

12-06-2019, 10:00	#12 (permalink)
leham Junior Member Join Date: Feb 2016 Posts: 28 Member: 2533922 Status: Offline Thanks Meter: 8	u3801 u3801 u3801 u3801 u3801 u3801 7 plus