How to configure Redmi 9 so that the screen does not turn off when inactivity

Xiaomi’s smartphones, including the popular Redmi 9, are famous for optimizing power consumption. However, aggressive power saving policies often cause the display to go out faster than the user expects. This can be extremely inconvenient when reading long texts, browsing recipes in the kitchen or while navigating. Standard settings do not always allow flexible control of the sleep timer, which forces you to look for workarounds.

The MIUI operating system that runs on Redmi 9 has hidden mechanisms that block the transition to sleep for certain applications or use cases. Understanding how the task manager and energy saving system work will allow you to customize the device exactly as you need it. We will look at standard methods, hidden engineering codes and installing specialized software.

Redmi 9’s 5020 mAh Lithium Polymer Battery can be discharged in 4-6 hours of continuous screen operation at maximum brightness, so you should only use constant glow modes when necessary when the phone is connected to the charger or in the power bank access zone.

Standard settings of the sleep timer in MIUI

The first step should always be to learn the basics of the system. In Redmi 9, the time management before the screen is turned off is in the display settings menu. The interface of MIUI 12 or more new versions may vary slightly, but the logic remains the same for the entire ecosystem. Here you can choose a fixed period of time after which the backlight goes out.

To access these settings, you need to open the Settings app and go to Screen. Find the Settings (or Screen Timeout) option. The system will offer a list of available intervals from 15 seconds to 10 minutes. The Never option on the standard menu is often not available without the use of special modes, which will be discussed below.

• ⏱️ Short timer (15-30 seconds) ideal for maximum battery savings during the day.
• ⏳ Average interval (1-2 minutes) is suitable for most normal use scenarios.
• 🕰️ Long delay (5-10 ) easy to read but requires charge control.

If you don't have the standard range and the screen goes out even when you choose the maximum value, the problem may be in the proximity sensor. Dirt on the screen or improperly pasted security glass can lock the sensor, causing the system to think that the phone is in your pocket, and force the lights to turn off. Clean the top of the display and check the sensor.

Using the Developer Mode to Prolong Screen Work

For more subtle configuration, Xiaomi Redmi 9 provides access to the extended developer menu, which is a hidden partition that allows you to change the parameters of animation, processor operation and, importantly for us, the behavior of the screen during charging. Activation of this mode does not require root rights and is safe for warranty.

To enter the developer menu, you need to quickly click on the build number seven times in the About Phone section. After the message “You became a developer” appears in the settings menu, a new option will appear in the “Additional” or “Extended settings” section.

Inside this section, you should find the option to Stay awake, which when activated, the smartphone display will not go out while the device is connected to a power source via USB or an adapter, which is a great solution for using the phone as a desktop clock, a smart home monitor or a navigator in the car.

Note that this function only works when you have an active charging connection. If you turn off the cable, the sleep timer will return to the standard values set in the display menu.

⚠️ Warning: Do not change other options unknown to you in the developer menu. DPI or changing the limits of background processes can lead to unstable application operation and system failures.

Third-party screen management applications

When the system is not enough, apps come to the rescue from the Google Play Store. For Redmi 9, there are many utilities that can force the screen to be turned on on on a schedule, when running certain programs or shaking the device, and they work on top of system constraints.

One popular solution is the Keep Screen On or Caffeine app, which works simply by creating a temporary stub file or using system APIs to simulate user activity, preventing a sleep timer from going off. Once installed, the app’s icon usually appears in the notification curtain.

• 📱 Control through the curtain: enable the mode with one touch without logging into the menu.
• 📅 Automation: the ability to set a schedule, for example, from 9:00 to 18:00.
• 🎯 Exception applications: Permanent screen settings for a specific software only (e.g., navigator only).

When using third-party software, it is important to pay attention to permissions. To work correctly, the program may need access to "Above Other Applications" or the right to change system settings. MIUI also needs to allow auto-run for such an application, otherwise the system will "kill" its process after a few minutes of operation to save energy.

The “Do not turn off the screen” function in specific applications

Many users don't know that some apps have a built-in sleep-free feature, which is true for video players, navigators and reading software. If the screen goes out while watching a movie, check the settings of the player itself, not just the system.

For example, on YouTube, VLC or MX Player, playback settings often have a “Do not turn off screen” tick in their settings. In navigation apps such as Yandex.Maps or Google Maps, this mode is turned on automatically when you start a route. If this does not happen, check if the battery settings limit for a particular application is worth the limit.

For text readers like FBReader or Moon+ Reader, the setting can be called “Keep the screen on.” This allows you to read books without touching the display every two minutes. In Redmi 9, these settings are often duplicated, so settings inside the app itself takes priority.

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If you use your phone as a digital photo frame, turn on the slideshow mode in the gallery. In many versions of MIUI Gallery, the screen does not go out while the photo slideshow is running.

Table of comparison of methods of turning off the screen

To make it easier for you to choose the right method, we have prepared a comparison table that will help you assess the pros and cons of each method in the context of using the Xiaomi Redmi 9.

As you can see from the table, the most versatile and safe way is to use the developer mode in conjunction with the charger. However, for mobile scenarios, when the socket is not at hand, it is better to rely on smart timers of third-party applications that can be quickly turned off.

Sensor problems and software failures

Sometimes the Redmi 9 screen goes out not because of the timer, but because of the wrong readings of the sensors. The light sensor can think that the room is dark, and reduce the brightness to zero, creating the illusion of turning off. The approach sensor can respond to glare or a case. In such cases, calibration helps.

To test the sensors, there is an engineering menu in MIUI: dial ##6484## in the Phone app. The hardware test menu will open. Select items related to the proximty sensor and light sensor, and run tests by covering the top of the screen with your hand.

If the sensors are working properly, but the screen continues to go out chaotically, perhaps the system has accumulated software debris or there was a failure in the process. system_ui. In this case, it can help to clean the cache or, in extreme cases, reset the settings to the factory.Be sure to back up important data before resetting.

⚠️ Warning: If the screen goes out and the phone is completely off (black screen, vibration, shutdown sound), this may indicate a battery problem or overheating of the processor, rather than the timer settings.

FAQ: Frequently Asked Questions

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The optimal strategy for Redmi 9 is to combine a standard timer of 2-5 minutes for everyday life and a developer mode of “Do not turn off the screen” in stationary use with a connected charger.