How to Fix iPhone 7 Broken Touch ID Hardware

iPhone 7 Home Button cannot be replaced - Error 53 Part 2

Whether through the introduction of Pentalobe screws or currently Y-type screws, or because, compared to Samsung, no original spare parts are sold: Apple does not make repairs yourself easy. This is not a new topic. A new annoyance now appears from the iPhone 7: You can no longer change the home button yourself.

Last year we reported on the “Error 53”: It was not possible to successfully restore after a software update from an iPhone with a non-original home button. This met with strong criticism internationally. Apple finally gave in with the iOS 9.3 update. Apple is currently being sued by the Australian Consumer Protection Agency.

Is Apple repeating a new type of “Error 53” on current models?

The iPhone 7 has a capacitive home button. This no longer works mechanically with a push of the button, but capacitively via the skin and electrical voltage. But what happens if the home button is defective?

So far it was at least possible to swap the home button on devices with Touch ID and continue to use the home button function. The only thing you had to do without the Touch-ID after the exchange.

Currently, only Apple can replace the home button on the iPhone 7 and iPhone 7 Plus. In numerous tests, we have found that third-party home buttons cannot even perform basic functions, such as simply “clicking”. Therefore you are dependent on the “Assistive Touch” function. It is already foreseeable that the Touch ID function will also be missing. Since the iPhone 5s, with which the Touch ID was introduced, Apple has reserved the right to reprogram the Touch ID after a replacement. The calibration machine developed by Apple must be used for programming. In terms of ensuring the security of personal data, this is of course exemplary from Apple. However, this is solved in a more user-friendly manner by other manufacturers.

Even the normal back function or the double-click no longer work after replacing the iPhone 7 home button with a home button from a third party. Even if two original home buttons are exchanged, the home button no longer remains “clickable”. Accordingly, this function is controlled by the software.

Third-party home buttons for the iPhone 7 have no function

We carried out several tests and got the following results:

  • The exchange of the originally installed home button with a home button from a third party is unsuccessful.
  • The exchange of the originally installed home button for an original home button is not successful.
  • The exchange of the originally installed home button with a home button from a third party and a subsequent DFU restore is unsuccessful. After dismantling the original home button, it no longer works either. In addition, the iPhone takes about three times longer to start than before. The original home button can only be used again after another DFU restore.
  • The exchange of the originally installed home button with an original home button and a subsequent DFU restore is not possible. When you dismantle the original home button, it no longer works either. In addition, it takes about three times longer to start the iPhone. The original home button can only be used again after another DFU restore.

What is it all about?

The programmable chip AD7149 (almost identical to the AD7142 chip from Analog Devices) is on the flex cable of the iPhone 7's home button. It should be possible to rewrite this chip with a DFU restore. This is apparently prevented by Apple. Why do we come to this assumption? Even after dismantling the original home button, it does not work at first. Only a renewed DFU restore brings functionality again. It is also noticeable that the startup process of the iPhone takes significantly longer if the non-original home button is installed.

The AD7149 programmable chip from Analog Devices

Conclusion on the iPhone 7 Home Button

Currently, only Apple - regardless of the Touch ID - can install a new and functional home button in the iPhone 7. However, there are no repairs listed separately, so that the entire display unit has to be replaced. From the customer's point of view, there are fewer options left to have repairs on their iPhone 7 repaired by themselves or by third-party workshops after the warranty period has expired.

Have you already had these experiences? Or maybe you have a new approach? We look forward to your comments and opinions, as well as suggestions on how we can carry out further tests.