How To Fix iPhone X Touch Screen Won’t Work Issue – On Motherboard

If your iPhone X touch screen won’t work any more, the first thing we should do is to force restart your iPhone X.

How to force restart iPhone X? Just take the following steps:

  • Press down the Volume Up button then release
  • Press down the Volume Down button then release
  • Hold down the side Power for about 10 second.
  • When the Apple logo comes to the screen, release the Power button

If the force restart doesn’t fix the touch screen no response issue, we could then try to replace a new screen.

In most cases, the force restart and replacing screen should solve the problem. However, sometimes it is the Logic Board that has been faulty. Under such circumstance, we should check the iPhone X Logic Board and fix the faulty parts.

Here we share an iPhone X whose touch screen won’t work with faulty on Logic board.

Check Logic Board

Tear down iPhone X screen, and then the Logic Board. First of all, we need to find out whether there are some obvious defects. We observe the Logic Board under a microscope and find no defects. All Logic Board parts are in good shape.

 

Then we check the digitizer PCB connector and measure its resistance. When comparing the values with standards, we find that all values are normal. That is to say, the digitizer PCB connector is OK.

The faulty part must be inside Logic Board. We need to check the inner parts of Logic Board.

Check Logic Board Inner Parts

Fix Logic Board on PCB holder and heat it up with a hot air gun. In this way we can take off the shield case.

After blowing Logic Board for cooling off, we measure the diode readings of the capacitors. Meanwhile compare the values with standards. Again, all values are normal.

Check Logic Board Inode Bitmap

We have no choice but to check the iPhone 11 Logic Board Inode Bitmap. On the Inode Bitmap, we can see that there are only two related parts untested, and they are the Inductor L5600 or the touch IC U5600,

Replace Inductor L5600

Since replacing an inductor is simpler, hence we begin with the Inductor L5600.

Before operation, we cover Logic Board with thermal-protective layer, so that the CPU and Power IC won’t be damaged during heating up. Then apply solder flux on L5600 and heat it up at high temperature. At the same time, take down the Inductor L5600.

Lastly, apply solder flux again and install a new L5600. It is easier said than done, but eventually, we have the new inductor replaced successfully.

Check Touch Screen

Since now power on with battery might cause short circuit, So we use DC power to boot up the phone in the first place. Rip off thermal-protective layer, and then connect screen with Logic Board. In this way the phone will boot up automatically. When we test the touch screen, it touches smoothly. The iPhone X touch screen won’t work issue has been solved perfectly.

We install the shied cover, Logic board and the screen back. Power on and test again, the touch screen works well.

For the whole operation process, please check the video below:

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