Why doesn't the screen light up when I come to WeChat message?

The reason is the vibration mode and system settings.

1. Vibration mode: When the phone is set to vibration mode, the screen will not light up to display a new message notification. You can adjust the vibration mode of your phone or turn it off so that the screen lights up when you receive a WeChat message.

2. System settings: Check whether the information reminder function is turned off in the mobile phone settings, enter the mobile phone settings, find the notification or sound and vibration options, and ensure that the notification settings of WeChat are turned on.