iPhone 6 no so common no touch issue

This time we are working on an iPhone 6 with strips on screen and no touch. Client want data recovery if it is not fixable.

As noted in first picture, there’s a dent on the black soft shield, touch ic is right under it.

Ok. Touch ic replacement, simple.

After touch ic replacement, problem still exists, so let’s replace touch ic power supply, the display ic.

Then the phone had touch. Cool! Rang the client and they paid immediately.

So I put it back and do final test before send it back, strips on the screen again!

So it didn’t fix it.

Let’s try replacing the touch ic, display ic again, and Broadcom touch ic.

Hook on power, fully shorted.

Put temperature sensor over the whole board, there’s no hot spot.

So it’s not a shorted cap. it either the board is bent and heat damaged it more, or solder balls under some chips are connected together causing the ground.

Remove the ICs I replaced, still shorted.

Ok. Now is the guessing game. Let’s start with the audio ic and WIFI chip, which are commonly damaged during touch ic replacement.

Still full shorted. Of course I wouldn’t damage these chips as I replace touch ic multiple times daily.

Ok. Try chips on the other side.

The backlight IC. Still fully shorted.

Hmmm. I can give up right now as you can see there are huge amount of chips have been removed

But the client want the data.

To me , it’s either refund the $150 which is no biggy  to me, but if I give up, client data is not retrievable. Data is always priceless.

Try harder.

Check all points for battery supply.

NFC power supply is the next suspect. Remove it and yay, cross connected solder balls.

Clear it, put all chips back. Touch and display works perfectly. I could stop here.

However I noticed there’s an 10ma current leak when battery is plugged in. It’s very minor and you won’t notice any difference during daily use.

But hey, it suggests there’s a short somewhere and let’s show some professionalism.

Still start with nfc power supply again.
Replaced one and 0 current leak when battery plugged in. The chip must has been damaged when there were grounded solder balls

Test again.

All fixed.

put all shields back.

You wouldn’t know it has under gone such a big surgery if I didn’t tell you, would you?