We will fix an iPad Air 2 with the fault like this: it cannot be charged before replacing its USB management chip, after the problem is sloved and assembling it, we find that it gets into IOS and sometimes screen turns red and roots itself.
As the USB management chip was replaced before, we worry about that the USB management chip is damaged or the solder is worse, so here we replace the chip again. But the problem remains the same, which suggests that USB management chip is workable.
Next we use the smallest peripherals method to exclude the faulty places. Unplug all the connection cable from other peripherals to motherboard, such as camera, sensitization, as shown in the picture.
Put the single motherboard with display flex cable on electric tester. After unplugging all peripherals and testing many times, the problem remains the same, which suggests that the problem is unrelated with peripherals.
Judging from my repair experience, after excluding the peripherals problems, damaged NAND FLASH and pseudo soldering could cause iPad red screen.
Problems are sure to happen at CPU and NAND FLASH. Next, we have to think whether to fix CPU or replace NAND FLASH. Under the rule of taking the easiest the first, I replace the NAND FLASH. The motherboard without NAND FLASH is shown in the following picture.
But after soldering NAND FLASH again, the problem remains the same. Now the problem is left to CPU. Re-solder CPU and test. The problem disappear.
When assembling iPad, I find new dropping marks, so I guess that the iPad has been dropped, which causes CPU damage. When other maintenance man was tearing USB management chip, the motherboard was heated and the damaged CPU is pseudo soldering.
Read more on www.vipfixphone.com
As the USB management chip was replaced before, we worry about that the USB management chip is damaged or the solder is worse, so here we replace the chip again. But the problem remains the same, which suggests that USB management chip is workable.
Next we use the smallest peripherals method to exclude the faulty places. Unplug all the connection cable from other peripherals to motherboard, such as camera, sensitization, as shown in the picture.
Put the single motherboard with display flex cable on electric tester. After unplugging all peripherals and testing many times, the problem remains the same, which suggests that the problem is unrelated with peripherals.
Judging from my repair experience, after excluding the peripherals problems, damaged NAND FLASH and pseudo soldering could cause iPad red screen.
Problems are sure to happen at CPU and NAND FLASH. Next, we have to think whether to fix CPU or replace NAND FLASH. Under the rule of taking the easiest the first, I replace the NAND FLASH. The motherboard without NAND FLASH is shown in the following picture.
But after soldering NAND FLASH again, the problem remains the same. Now the problem is left to CPU. Re-solder CPU and test. The problem disappear.
When assembling iPad, I find new dropping marks, so I guess that the iPad has been dropped, which causes CPU damage. When other maintenance man was tearing USB management chip, the motherboard was heated and the damaged CPU is pseudo soldering.
Read more on www.vipfixphone.com
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