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Solved: Unknown Error on iPad 4 when Rooted by iTunes.

We received an iPad 4 with unknown error (9) when rooted by iTunes, the picture is as following



Judging from my repair experience, if it reports unknown error (9), NAND FLASH power supply or NAND FLASH itself is damaged. First measure each power supply of NAND FLASH. They are normal. Next, remove NAND FLASH and deal with the solder tin and black glue, as shown in the picture.



Assemble the removed NAND FLASH on a workable motherboard to root. It still reports unknown error (9). I can be sure that the NAND FLASH is faulty. Put new NAND FLASH on NAND FLASH testing jig to find out the information and series number. The software operation interface of NAND test fixture is shown in picture. Then solder the NAND FLASH with information and series number and on motherboard, as shown in the picture.



Connect computer to root, as shown in the picture.


It is activated and gets into IOS system normally, as shown in the picture. Test all the functions. They are normal. Trouble is removed.



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