iPhone 7 charging Anyone can help??

[gjizaqin]

Got iphone 7 from customer with battery draining fast, so I changed U2 (U4001) The phone stopped charging. I tried changing several IC's from different suppliers, with some it failed to even start. After trying some of my collegues to repair it they damaged one of the ic's Pin and now after placing new IC the phone charges when off. And when Turned on it shows only PHONE CHARGED on the screen when you connect cable, and it disappears immediately after. Strangely phone is recognised by Itunes, and i was able to backup the phone.
Can someone suggest me what to do.

[gjizaqin]

sorry wrong pin selected,
this one is missing

[BouRRi_GSM]

Originally Posted by gjizaqin

sorry wrong pin selected,
this one is missing

white pin are NC so no problem.
when u replace new tristar, better clean ic from original ball, and reball it yourself before.
original ball need higher temperature, and ic can't take his place by himself.
so sometime will cause problem.

[gjizaqin]

Originally Posted by BouRRi_GSM

white pin are NC so no problem.
when u replace new tristar, better clean ic from original ball, and reball it yourself before.
original ball need higher temperature, and ic can't take his place by himself.
so sometime will cause problem.

Ok im gonna try this and show the results here.

[ninos22]

Originally Posted by gjizaqin

Got iphone 7 from customer with battery draining fast, so I changed U2 (U4001) The phone stopped charging. I tried changing several IC's from different suppliers, with some it failed to even start. After trying some of my collegues to repair it they damaged one of the ic's Pin and now after placing new IC the phone charges when off. And when Turned on it shows only PHONE CHARGED on the screen when you connect cable, and it disappears immediately after. Strangely phone is recognised by Itunes, and i was able to backup the phone.
Can someone suggest me what to do.

What is the point of replacing an chip without test / measure basics?

The battery drain can be anything.

[gjizaqin]

Originally Posted by ninos22

What is the point of replacing an chip without test / measure basics?

The battery drain can be anything.

Because of experience I supposed it was the problem. And after replacing Tristar it doesnt drain battery so it was U2 fault.

[gjizaqin]

Originally Posted by BouRRi_GSM

white pin are NC so no problem.
when u replace new tristar, better clean ic from original ball, and reball it yourself before.
original ball need higher temperature, and ic can't take his place by himself.
so sometime will cause problem.

I tried this and it doesn't seem to work, still same problem. Charges when turned off until it turns on, and then it doesn't charge at all.

[ninos22]

Originally Posted by gjizaqin

I tried this and it doesn't seem to work, still same problem. Charges when turned off until it turns on, and then it doesn't charge at all.

Tristar is a high speed switcher, Trigris is the charger, so you have to check one by one.

[7Axis]

Originally Posted by gjizaqin

Charges when turned off until it turns on, and then it doesn't charge at all.

Connect your logic board to a power supply, boot the phone... Check how much amperage it's drawing after the boot sequence is finished once your phone is on the lock screen.


When powered off the only lines that draws current are PP_VCC_MAIN and PP_VCC_BATT, if your phone charges correctly while turned off then you know these lines are ok, you have over a hundred different lines that has current going through when turned on, any of these could be shorted and drawing too much current from the battery to attempt charging it.