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Question: Does changing u2 ic or memory chip will make touch id to shop working? My iphone 5s suddenly turned off. When I insert charger it turns on and show apple logo and then turn off and then this whole process starts again (turning on>show apple logo>turn off) and it continuous as long as charger is inserted. When take out charger, phone turn off and no matter which button combination you use and how many times you use, it doesn’t turn on. If I do DFU mode method, although screen stays off (black) it tries to restore but only to give an error each and every time. So I went to technician and he said your memory or u2 ic is at fault and need to be changed. But after changing it he now told me that touch id won’t work now! But as touch id is linked to processor so is it possible that changing u2 ic or memory chip make touch id stop working? Or it’s his fault and he damaged something, bcuz before it touch id was working 100% ok!!
@c9679 is correct. Replacing U2 (Tristar chip) does not affect Touch ID. Also reballing or replacing the NAND (what they are calling the memory IC) does not prevent Touch ID from working again either. Normally rebooting can be, most commonly: 1- Corrupted software (needs restoring); 2- Bad or disconnected battery (reconnect or replace with good quality battery); 3- Bad charging dock (replace); 4- Board level damage near battery connector (replace missing or corroded component); 5- Tristar (U2); 6- Possibly corrupted NAND (needs reballing/replacing AND restoring); Etc. If Touch ID stopped working, then either: A- The board has been replaced, or B- The home button has been replaced because they lost it/mixed it up with another one or damaged it during repair. OR.. C- They restored without the home button attached. In which case you need to restore again with home button connected. A- and B- cannot be fixed unless Apple (Apple Store only) replaces the screen together with the home button, as them alone can pair a new home button / Touch ID to the existing CPU.
The touchid is linked to the cpu, changing nand won’t change imei changing baseband, nand and cpu will change imei more likely ur board has been swapped with another one if ur imei doesn’t match what it originally was… if ur board has been swapped without swapping the home button as well to the original boards home button then touchid won’t work Reprogramming nand doesnt affect touchid, u2 doesn’t affect touchid What was the error when you restored and did you try a new battery before all of this???
