iPhone 6s No Touch

[mawaqas]

hi i got an iphone 6s came in for no touch repairs. I have tested all the filters mentioned on the schematics and all of them are intact but I have no touch. The L4240 ic circled in red. i have not been able to test.

Any help from professinals will be highly appricated.

[mb83]

i have same issue... no such. I've changed u4240 but no luck...

[mawaqas]

thanks for your input mb83

[mawaqas]

could it be linked to the display ic U4000? it is a display PMU is and PP5V1_Touch_VDDH comes out of there......

[mb83]

Bro I've changed u4000 and still nothing... I don't have any ideas.

[mb83]

in one case I replaced battery and touch start to working fine... I don't know why, I don't know how but iPhone working fine. Maybe you try.

[mawaqas]

thanks bro ill try to replace the battery and let you know. We will try to figure this together bro

[vinse]

Originally Posted by mawaqas

hi i got an iphone 6s came in for no touch repairs. I have tested all the filters mentioned on the schematics and all of them are intact but I have no touch. The L4240 ic circled in red. i have not been able to test.

Any help from professinals will be highly appricated.

i'm facing same issues working on it actually all filter ok like you
this 2 days after backlight job and big audio ic remplacement .

-test the resistor on top of your red mark you have to get theire 1V8_touch
personally i don't get that voltage

did you notice weird value one diode mode aon J4200
on pin 28 LCM_TO_CHESTNUT_PWR_EN_CONN when i shut down the phone
remove battery the value on this one is very low and increase when the board get colder i dont have board to compare so only guessing

[mb83]

i've even tried to replaced connector... no luck

[vinse]

Originally Posted by mb83

i've even tried to replaced connector... no luck

hello i don't think it's connector issue

for that you don't have to replace anything before proced by excluding things
so first
-check for filter visualy and beep mode
-diode mode restisantance on each pads of the J4200
-then voltages in my case the PP1V8_TOUCH not present and the other even
-so it can be several things

Chestnut (for me i think at him first )
but chestnut provide LCM too so can it be half faulty ??
or caps on the messon line
PP5V7_MESON_AVDDH , PN5V7_LCM_MESON_AVDDN
from Chestnut (faulty,shorted )
can also be the AP_TO_TOUCH_RESET_CONN_L so you have to check filter
FL4134 next to the J4100

Pmic (faulty ) but i doute

or spi line Brocken (thats *****)

please do those test seriously and reply your results

[mb83]

Bro read my posts... all of these things i did before. We dont have any new ideas so dont write you brilliant ideas becouse i check all of these in first place. I,m stuck, i dont know where to look.

[mawaqas]

Originally Posted by vinse

hello i don't think it's connector issue

for that you don't have to replace anything before proced by excluding things
so first
-check for filter visualy and beep mode
-diode mode restisantance on each pads of the J4200
-then voltages in my case the PP1V8_TOUCH not present and the other even
-so it can be several things

Chestnut (for me i think at him first )
but chestnut provide LCM too so can it be half faulty ??
or caps on the messon line
PP5V7_MESON_AVDDH , PN5V7_LCM_MESON_AVDDN
from Chestnut (faulty,shorted )
can also be the AP_TO_TOUCH_RESET_CONN_L so you have to check filter
FL4134 next to the J4100

Pmic (faulty ) but i doute

or spi line Brocken (thats *****)

please do those test seriously and reply your results

thanks for your reply. I have tested PIN 14 at J4100 for PP1V8_TOUCH_ and im not getting 1.8V there also checked FL4134 and FL4131 both good

[mawaqas]

Originally Posted by mawaqas

thanks for your reply. I have tested PIN 14 at J4100 for PP1V8_TOUCH_ and im not getting 1.8V there also checked FL4134 and FL4131 both good

Originally Posted by vinse

hello i don't think it's connector issue

for that you don't have to replace anything before proced by excluding things
so first
-check for filter visualy and beep mode
-diode mode restisantance on each pads of the J4200
-then voltages in my case the PP1V8_TOUCH not present and the other even
-so it can be several things

Chestnut (for me i think at him first )
but chestnut provide LCM too so can it be half faulty ??
or caps on the messon line
PP5V7_MESON_AVDDH , PN5V7_LCM_MESON_AVDDN
from Chestnut (faulty,shorted )
can also be the AP_TO_TOUCH_RESET_CONN_L so you have to check filter
FL4134 next to the J4100

Pmic (faulty ) but i doute

or spi line Brocken (thats *****)

please do those test seriously and reply your results

Check FL4105 for PP1V8_TOUCH mine is ****n. Im going to replace it and see if i get PP1V8_TOUCH

[mawaqas]

found short on PP1v8 Touch at FL4105. when the phone is turned on it beeps when i connect FL4105 to the ground!!!

[vinse]

Originally Posted by mb83

Bro read my posts... all of these things i did before. We dont have any new ideas so dont write you brilliant ideas becouse i check all of these in first place. I,m stuck, i dont know where to look.

Dear mb83

thank you for your message .... i was stuck excactly on this too and i wanted to compare with others to see what i miss not trying to value my self !!

you'r without a doute smarter than me so ...


my only expectation was learning and sharing simple as that,you look for solution ,i look for brainstorming ,compare ,evoluate.
so i will keep my brillante ideas for my self next time .

as i always says and write that's not my job ,i do this only for fun .

take care