iPad Error: iPad 4 Touch function not working Problem - VIPPROGRAMMER

As we know, The iPad Whatever the version is always sounds deluxe. However,if your iPad 4 Touch function not working when you are received it, that isn’t fun anymore. This problem will not only disturb your iPad activity but can also lead to iPad damage. Many iPhone users reported the same thing, so you are not alone. Here, vipprogrammer are going to share the solutions to get rid iPad 4 Touch function not working issue.

Step 1: Disassemble the iPad 4 by opening tool and then use multimeter to test the diode data of PP3V0_GRAPE, it's normal. Then test the PP18V_GRAPE, it shows 0V, which is not normal, as shown in picture.

Step 3: The PP18V_GRAPE is output by U3000 chip, the picture as follows:

Step 4: After test U3000, we can find that when it open signal, the 5 pin PM_BOOST_EN has no voltage, so the chip not working.

Step 5: The PM_BOOST_EN turn on the signal is made out of U3101 chip, so we replace the U3101 chip, and then it outputs normally. You can check it under the microscope as shown in picture.

Step 6: 3V open signal,  Now the PP18V_GRAPE can be normal output.

Step 8: Assemble the iPad, and test it, we find there is a horizontal line that doesn't slide. After we use multimeter test it, we can find that the touch adapter 9 pin of J3011 are infinitely large, as shown in picture.

Step 9: We judged it to be disconnected, there is a measuring point on its periphery, jump wire on it, the problem was solved.

Step 10: Install the iPad, and test it, the touch function back to normal. As shown in picture.

Tips:  If you want know more details, you can read on VIP Pro Shop Team. all of these phone repair tools, and you can find it.