Yesterday wrote an article about [Apple confused operation: cancel the noise reduction function, the old iPhone open system downgrade can brush iOS14] article, many friends want to try it, mainly iOS15 experience problems, in addition to iOS14 is very friendly to old devices, I have to say that in 2022, Apple is still optimizing the iPhone too smooth BUG!
Can all iPhone Xs Max users downgrade to iOS 14.1? Of course not. The current latest iOS system version is iOS 15.2.1, but Apple has closed the verification channel of iOS 15.1.1 and all systems below, but there is a fish that has slipped through the net, that is, the iPhone Xs Max National Bank Edition, so far the iOS 14.1 version of this model verification channel is still open.
Here many bank version of the iPhone Xs Max users can't help it, have begun to flash the machine, most of the users who meet the above requirements have failed to flash the machine, prompting "Error: request SHSH failed...", even if you try several times is the same result, why is the verification channel open, but the brushing machine still fails?
Through the exchange and feedback of most of the iPhone Xs Max flashing users, the conclusion is that not all versions of the National Bank of China iPhone Xs Max can be successfully flashed and downgraded, only the two networks of iPhone Xs Max models can be flashed downgraded to iOS 14.1 system, to know that there are not many iPhone Xs Max models with the two conditions of "National Bank" and "Two Networks".
(Source digital rice bowl public number article comment area)
Here also to say, this iOS 14.1 version of the channel open is not a matter of recent days, digital rice bowl on the previous article of the comment area has user feedback has been open for several months, but the number of supported models is very small all not widely disseminated.
Finally, brushing needs to be cautious, remember to back up the data before downgrading, so as not to cause data loss due to flashing failure! If you are the main machine, it is not recommended to brush the machine frequently.