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Released September 25, 2015. Model A1688/A1633. Repair of this device is similar to previous generations, requiring screwdrivers and prying tools. Available as GSM or CDMA / 16, 32, 64, or 128 GB / Silver, Gold, Space Gray, or Rose Gold options.

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Touch ID Repair Theory

Hey guys, I have a thought on repairing the touch ID on an iPhone just in general. So, since the touch ID home button and CPU are essentially ‘tied’ together with a unique ID which I’ve heard is encrypted, and obviously button replacement warrants the touch ID as useless due to different ID’s, but, say someone who were to have enough skill in SMD rework on logic boards, could the CPU possibly be replaced and then the new home button could be paired with the new CPU. There’s most likely other chips that will need replacing but I just thought about it and there seems to be absolutely nothing online anywhere about it other than repairing the button flex which could be missing as some 2nd hand iPhones or logic boards don’t come with them.

The reason I ask is that I have a couple dead logic boards at home and I’m a begginer getting into SMD rework and I’m looking at buying iCloud locked boards, replacing the respective chips to remove the lock and since a lot of these don’t come with home buttons or no touch ID, it really devalues the phone. So I thought I’d get some view and opinions on it. (yes it may not be cheap or economic) but I just want to know if it is possible. Thank you

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What you propose is plausible, doable even but not practical.

It’s the same issue as with iCloud lock; you can’t make something out of nothing.

If you had a good HB and it’s paired logic board, you could move over the CPU/SDRAM/NAND/BBCPU/EEPROM to another board. However, that is a lot of work and the opportunities to mess up await you at every corner. It’s much simpler to just use/repair the board that has a working HB paired to it.

This is what I usually reply when people ask the “wouldn’t it be possible to swap some IC’s” type of question:

Essentially, the CPU/NAND/Baseband CPU and EEPROM are all tied together with a secure code. While you can reprogram the NAND, there is no such access to the CPU or Baseband CPU. Therefore, the only way to make a logic board unlocked (''or in this case, TouchID swap'') is to transfer those IC’s from a non locked board…that’s a whole lot of work for nothing as you haven’t made anything new, you risk damaging both boards (this is a very difficult repair with low success rates) and it would have been easier to just transfer the unlocked logic board in the first place.

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Changing the cpu wont allow u to reprogramme a new touchid… u would need a cpu with an already paired touchid home button supplied with it.

If you have iCloud locked boards practice on those first see if u can remove and replace the cpu, baseband, eeprom etc :) if u have the skills and ability to replace those lol I'm pretty sure u wont need to ever worry about jobs fixing touchid.

Sorry no it's not possible, replacing the cpu will not allow u into the secure enclave within a cpu which has the pairing information for the baseband and touchid and other secure information.

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I suppose it could be possible to find them together already paired but I'm not 100% sure. Also I'm purchasing a begginer level microscope as I have a usb microscope camera thing which is awful haha. Do you have any tips in general or recommendations when it comes to rework? Thank you :)


I have lots of tips best at this point would be whatever u do dont heat or even touch the CPU lol... outside of China there are very few people able to transplant the cpu on a 6 or a 6s and even in China there is a large fail rate and these people have years and years of experience lol

I have more tips that may help u but get urself a decent microscope and research as much as u can before u touch a board with any kind of tool... try as much as possible to learn as much as u can about a problem or a fault on the phone before u dive in and do harm slightest thing u do inside could introduce other problems, so if u have customers ask questions find out hints on what's happened what the exact history is and know what ur getting into before u even open the phone... get ur microscope and post again on here and welcome to a whole new world

Research everything even the microscope is it going to be suitable for u? Will u be able to see everything u need to see and in enough detail will the light be sufficient? Will there be enough room underneath to work under it with a soldering iron or hot air? Will it hurt ur neck if u use a Barlow lens and it's too high up lol


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So basically the roundabout way to replace the motherboard?

If you can find the home button attached to a board, just replace the board then. I don’t see any point swapping the chips and basically ruin the board.

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