What should we do to repair the iPhone 7 Plus no service failure?
We received an iPhone 7 Plus and the fault description was no service. After insert the SIM card, the iPhone 7 Plus always in searching, and it has no IMEI when dialing the *#06#. Check Settings on iPhone, there are IM and Modem Firmware numbers. After reset the iPhone network settings, the problem still there. How to repair it ?
For this fault，please don't flash the iPhone first, if the iPhone baseband CPU has some problem, then it will report unknown error 4013 on iPhone 6S and above, for 7 and 7P, we need to notice iPhone baseband 1.0V power supply circuit. If iPhone baseband power supply is short circuit, then basically it's caused by damaged iPhone CPU, so we need to measure the resistance for this circuit before we start to repair. For an iPhone with an iTunes 4013 error, we can heat iPhone baseband power, and then flash it.
Open the WUXINJI Dongle, and then compare with the iPhone schematic diagram and iPhone motherboard bitmap to measure the iPhone circuit line power supply. After measurement, all power supply on the iPhone baseband power tested are normal, we need to re-install the iPhone baseband CPU. As shown in picture.
Because it is very close to main CPU, we need to do a heating insulation for the CPU. Use QUICK 861DW hot air rework station to heat iPhone CPU for a while, and then use BGA graver to gently remove the glue. We can remove the inductor on the right side fist and then insert the blade, or we can insert the blade in the slot，we'd better choose the thin blade. When heated it with hot air gun, we blow from the side of the CPU to the card slot. When we need to pay it, we can select a component around the baseband as a reference, and when the tin of reference begins to melt, we can start to pry into the baseband. As shown in picture.
There are many empty on the iPhone baseband CPU, observe it under the microscope, and then compare it with iPhone bitmap, there are many pins missing. Apply some lower temperature solder paste on the solder pad, and then soldering the iPhone baseband CPU with solder paste and glue, install it to the iPhone motherboard. After the iPhone motherboard is cooled, use digital multimeter to test whether the peripheral components short-circuit, so you can determine whether the chip has been installed intact.
For the first time, we choose turn iPhone on by DPS DC power supply, after everything's okay, install the iPhone, and then test the iPhone. This iPhone 7 Plus is a baseband failure caused by the iPhone baseband CPU virtual weld, after re-weld it, the failure has been solved.
Get more professional guide for cell phone repair on www.vipfixphone.com.
For this fault，please don't flash the iPhone first, if the iPhone baseband CPU has some problem, then it will report unknown error 4013 on iPhone 6S and above, for 7 and 7P, we need to notice iPhone baseband 1.0V power supply circuit. If iPhone baseband power supply is short circuit, then basically it's caused by damaged iPhone CPU, so we need to measure the resistance for this circuit before we start to repair. For an iPhone with an iTunes 4013 error, we can heat iPhone baseband power, and then flash it.
Open the WUXINJI Dongle, and then compare with the iPhone schematic diagram and iPhone motherboard bitmap to measure the iPhone circuit line power supply. After measurement, all power supply on the iPhone baseband power tested are normal, we need to re-install the iPhone baseband CPU. As shown in picture.
Because it is very close to main CPU, we need to do a heating insulation for the CPU. Use QUICK 861DW hot air rework station to heat iPhone CPU for a while, and then use BGA graver to gently remove the glue. We can remove the inductor on the right side fist and then insert the blade, or we can insert the blade in the slot，we'd better choose the thin blade. When heated it with hot air gun, we blow from the side of the CPU to the card slot. When we need to pay it, we can select a component around the baseband as a reference, and when the tin of reference begins to melt, we can start to pry into the baseband. As shown in picture.
There are many empty on the iPhone baseband CPU, observe it under the microscope, and then compare it with iPhone bitmap, there are many pins missing. Apply some lower temperature solder paste on the solder pad, and then soldering the iPhone baseband CPU with solder paste and glue, install it to the iPhone motherboard. After the iPhone motherboard is cooled, use digital multimeter to test whether the peripheral components short-circuit, so you can determine whether the chip has been installed intact.
For the first time, we choose turn iPhone on by DPS DC power supply, after everything's okay, install the iPhone, and then test the iPhone. This iPhone 7 Plus is a baseband failure caused by the iPhone baseband CPU virtual weld, after re-weld it, the failure has been solved.
Get more professional guide for cell phone repair on www.vipfixphone.com.
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