Excuse me, how do I downgrade my vivo Y55L system?

Steps: Enter the vivo official website - service - enter the model - resource in the search box - flash the firmware package of the mobile phone, if the version of the firmware upgrade package on the official website is lower than the software version of the mobile phone, you can downgrade; If the software version of the firmware package on the official website is higher than the software version of the mobile phone, please go to the after-sales service center to flash the phone, and the after-sales service center address query method; Go to mobile phone settings --- more settings --- after-sales service.

Method 1: Enter the official website of vivo -- Service -- enter the model -- resource -- flash the firmware package of the mobile phone in the search box, if the version of the firmware upgrade package on the official website is lower than the software version of the mobile phone, you can downgrade; If the software version of the firmware package on the official website is higher than the software version of the mobile phone, please go to the after-sales service center to flash the phone, and the after-sales service center address query method; Go to mobile phone settings --- more settings --- after-sales service.

Method 2: Turn off the mobile phone first, and then press the volume + button of the mobile phone at the same time"with"Power on button"(also known as the power button) after the vivo phone logo appears for 5 seconds, release the button and enter recovery mode. 2. Select Wipe Data Factory Reset, select Wipe Cache Partition after the wait screen jumps, and select Reboot System Now when finished.

You can downgrade with your computer.

After the phone is rooted, the system can not be upgraded normally, reason:

1. Corrupt data when rooted.

2. The system data is changed or cleared after root.

Solution or steps: Flash the official firmware and get ready.

1. Ensure that the mobile phone has sufficient power (more than 70%);

2. Back up personal data (contacts, text messages, apps, etc.) in your phone;

Method steps: 1. First, copy the package to the root directory of the mobile phone memory card.

2. In the shutdown state, press and hold the power button and the volume down button at the same time, after about ten seconds, yellow letters on a black background will appear on the screen, which means that the phone has entered recovery mode.

3. Use the volume up and down buttons to move the cursor to the "Manually select installation package" position, and click the power button to confirm. Next, use the volume up and down buttons to select the installation package, and click the power button to confirm.

4. Just wait for yourself to finish, the phone will always keep the screen lit during the machine, in addition to the scrolling yellow text, there is also a progress bar with a blue key color displayed below the green robot. The words "Installation Completed" will be displayed at the bottom of the final screen, the machine is complete, 5. Select Reboot the system immediately according to the prompts, and it is complete.