Apple can only be brushed to the higher version, can t it be brushed back to the lower version?

I don't know about this, but that's what the moto smartphone looks like. But that's called a BL grade. As for Apple, such a problem should be solved.

Yes, but it's troublesome.

Supplements: 1. In order to realize the system degradation and recovery of the Apple mobile phone system, it must be realized within the specified time, which can become the verification period; As long as it is within that time period, even if the device is upgraded, it can be lowered and the version can be lowered. Once this port is down, it is not possible to revert to a lower version of the system.

2. For example: not long after the ios7 system came out, update the phone to the latest ios7 system, and before the more advanced system than ios7 comes out, you can go to the after-sales service to detect whether it can be downgraded to ios6. Or you can try to restore the backup before upgrading the system, but it is not recommended to do it yourself, which is risky.

1. Solution:

You can't downgrade after upgrading, and Apple phones can't be downgraded according to official regulations after upgrading.

Downgrading by flashing the machine is risky, and sometimes it will become a brick, so it is not recommended to operate.

Jailbreak flash, this will not be under warranty after Apple officially discovers.

Second, the principle of operation:

The system is upgraded from low level to high level, and if it becomes advanced, it will not be able to go back to low level.

Unofficial operation Apple will no longer warrant.

First of all, it depends on whether the current system can be jailbroken, and the downgrade requires jailbreaking;

1. Drop 613 is no shsh, that is to say, the general mobile phone can be dropped, but the original mobile phone card serial number.

2. Drop 7-8 is to shsh, go to Aisi to check, which shsh has backup;

3. If there is no SHH backup, if you have strong hands-on ability, you can extract the SHH of the local machine on Mac, and find it in the forum; Generally, mobile phone stores don't, so it's easy to either ask for someone or do it yourself;

4. There is a risk of downgrading, such as improper operation, you can only flash the latest system, and there is no jailbreak.

Is Lanzhou a Hong Kong or mainland version? There is a danger of downgrading, so it is recommended that Lanzhou go to the local after-sales service to get the Hong Kong line, which is a global joint warranty, and the mainland version is a Chinese joint warranty, if Lanzhou is the version of other regions, I dare not say anything, after all, the danger of downgrading is very great.

If the Apple phone has not done shsh, it can't go back to the old version.

This one requires shsh in order to be downgraded.

At present, it can only be flashed back to iOS10, and other versions have turned off verification 1, turn off the phone, and then press and hold the [Power Button] and [Home Button] at the same time for 10 seconds.

After seconds, only release the [Power Button], and press and hold the [Home Button] for 10 seconds.

3. Release the home button.

4. Open iTunes, when prompted that the phone has successfully entered recovery mode, press and hold the "Shift" key on the keyboard, and click the "Recover" button at the same time, select the corresponding firmware, and perform the flashing operation. Note: Remember to back up your data.

OK. 2. Run iTunes and connect the device, click [iPhone] in the upper right corner to enter the device summary page.

3. Click [Back Up Now] to back up important data on your device, just in case. For a more detailed backup tutorial, please refer to How to Backup Important Data of iPhone.

4. Then press and hold Shift on the keyboard while clicking the [Update] or [Restore] button on the iTunes interface.

5. Select the corresponding version of firmware to downgrade. What should be emphasized here is that shift+update, the **and** in the device will be retained, but the app and address book will all be emptied. So be sure to do a good job of backing up your data.

6. Wait patiently for the recovery, and then iTunes will prompt a successful downgrade to.

7. Vulnerabilities in earlier versions may cause information leakage to users.

How to downgrade the version of the Apple system, it does not need to be operated by a computer, and it can be completed with a mobile phone.

How to reduce the version of the Apple system, this method is simple and practical, and most people don't tell him.

Is yours 3 or 4 if you back up shsh it's good to come back.

After the iPhone is flashed, the system version will be updated to the latest (the latest is the iPhone flash steps:

2. Put your phone into recovery mode

1. Press and hold the power button first, and when the shutdown option appears, please slide to power off;

2. Then press the power button to turn on the computer, the Apple logo will appear on the screen, do not release the power button;

3. Then press and hold the home button on the home screen until the screen goes black.

4. When the screen is black, please release the power button and continue to press and hold the home button on the home screen until iTunes on the computer side shows "An iPhone in recovery mode has been detected";

Note: If you can't enter the recovery mode, please do it several times.

Yes, [why can't the system be used after the iPhone is flashed].

This is a firmware flashing failure, and the workaround is as follows:

1. The mobile phone enters DFU mode, steps: when the phone is turned on, connect it with the computer with a data cable. Press and hold the power off button for 2 seconds; Then, press and hold the power off button and the home button at the same time for 8 10 seconds; Finally, keep holding the home button for 15 seconds.

2. Check whether you have entered DFU mode correctly: In DFU mode, the phone is black. If it doesn't work, redo the first step.

4. A window will pop up after iTunes recovery is completed"Your iPhone has been restored, and the window will automatically close after 10 seconds", close this window, and then unplug the data cable, do not use the computer to activate the iPhone, activate the system on the mobile phone will be purer.

Original system? It should be stopped.,The current official launch is the preview version.,There are a lot of problems with this version.,It's recommended not to brush.,Now the official is doing the system.,Just wait more.。

iPhone can only flash the firmware that has not been turned off for verification 4S and above models can only be flashed Nothing else can be flashed If you brush the lower version, there will be a 3194 error.