The Xiaomi Redmi 4X is one of the brand’s most popular budget smartphones, but even it has hidden features that many users are unaware of, including touch key highlighting (navigation buttons at the bottom of the screen), which is often manually activated on the Redmi 4X, unlike flagship models where this option is available out of the box.
In this article, you will find 4 proven ways to turn on the backlight, including hidden MIUI settings, engineering menus and solutions for cases where the buttons do not glow even after all the manipulations, we will also discuss why the backlight can turn off on its own after updating the firmware and how to fix it without resetting.
If you've tried to turn on the backlight through standard settings and it didn't work, don't rush to get your phone repaired. 80 percent of the time, it's software-based, and we'll show you how to do it.
1. Standard method: MIUI settings
The easiest method is to use the built-in MIUI options. However, on Redmi 4X, the path to these settings is not obvious, and in some versions of the firmware, the item is completely hidden.
- Open the settings → Additional settings.
- Scroll down and select buttons and gestures (in some versions of the Navigation Buttons).
- Activate the button light switch or Night light.
If you don't have one, don't worry. It means your version of MIUI doesn't support standard on. Go to the following methods.
An important nuance: on some firmware, the backlight only works when the screen is active (i.e., the buttons glow while you interact with the phone, and go out after 2-3 seconds of inactivity).
2. Engineering menu: hidden settings of backlight
If the standard method didn’t work, try activating the backlight through the engineering menu, which works on 90% of Redmi 4X firmware, but you need to be careful – incorrect settings can cause malfunctions.
Instructions:
- Open the Phone app and enter the combination: ##36446337###
- You will be taken to Engineer Mode. Go to Hardware Testing → LCD.
- Find Button backlight (or Key light) and set 255 for maximum brightness.
- Save the settings and restart the phone.
If the backlight doesn't work after the reboot, check if the settings in the engineering menu are reset, and sometimes MIUI automatically returns the values to the factory after the reboot.
What to do if the engineering menu is not opened?
⚠️ Note: Do not change other options in the engineering menu unless you know their purpose. For example, incorrect settings of the Touch Panel can lead to a broken screen sensor.
Applications for illumination control
If you don't want to go through the settings, you can use third-party utilities.
- 🔹 Button Mapper -- not only allows you to turn on the backlight, but also reassign navigation buttons. 4X rootless.
- 🔹 Key Event Display - displays button presses and controls their backlighting. Requires permissions for special features.
- 🔹 MIUI Hidden Settings – Reveals hidden firmware options, including backlight control.
Instructions for Button Mapper:
- Download the app from the Play Market.
- Run it and give access to Special Opportunities (in your phone settings).
- Choose the Navigation Bar → Button Backlight.
- Set Always On for constant lighting or set the timer.
The downside of this method is that applications can drain the battery faster because they run in the background, and if you notice a high charge charge charge, roll back to standard settings.
✅ Check the reviews about the application (ranking above 4.0)
✅ Download only from the official store (Play Market or AppGallery)
✅ Check the permissions (no access to the permissions) SMS or call)
✅ Make a backup of settings (Settings) → Additionally. → Backup)
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4. Problem Solving: Why the backlight doesn't work
If neither of these methods worked, the problem could be hardware or software, and let's look at the underlying causes and solutions:
| Problem. | Possible cause | Decision |
|---|---|---|
| The lighting is not turned on in any way. | LED burned or board damaged | Contact the service center (replacement of the button plume) ~1500₽) |
| The lighting flashes or works unstablely | Poor plume contact or damage to flexible cable | Disassemble the phone and check the connection of the plume |
| The lighting is turned off after the update | Resetting MIUI settings when updating | Repeat the settings through an engineering menu or application |
| The buttons only glow when pressed. | Energy saving mode turns off constant lighting | Disconnect the battery → mode of energy saving |
If you suspect a hardware malfunction, try the following:
- Connect your phone to charge – sometimes the backlight doesn’t work when the battery is low (less than 15%).
- Check if the buttons are responsive to pressing (even without backlighting). If not, the sensor is a problem.
- Light a flashlight on the button area - if you see a faint glow in the dark, then the LEDs work, but their brightness is lost in the settings.
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If the backlight stopped working after the phone fell, don’t try to disassemble it yourself. On the Redmi 4X, the button plume is very fragile and easily breaks when you unscrupulously dismantle it.
5. Alternative solutions: if nothing helps
If all methods are exhausted, but the backlight still doesn’t work, consider these options:
- 🔧 Custom Recovery firmware (TWRP) And then you can install modified firmware (like LineageOS), and they often have backlights out of the box".
- 🔧 Replacement of the button plume – if the problem is hardware, it is the cheapest solution (price of the part) ~500₽).
- 🔧 Using Virtual Buttons Through Settings MIUI (Settings → Screen. → Virtual buttons. They don't require physical lighting.
- 🔧 Backlit stickers are a temporary solution for those who don't want to repair their phone.Sold on AliExpress (~300₽).
Firmware Warning: Installing custom firmware will void the warranty and may result in a phone blink (completely inoperable).
If you decide to firmware, here are the minimum requirements:
- Unlocked bootloader (Bootloader).
- Installed TWRP Recovery.
- A backup copy of the original firmware.
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Before firmware, check the compatibility of custom firmware with the Redmi 4X (santoni) model. The wrong version can bring the phone down.
6. Frequent questions and myths about backlighting
There are a lot of rumors around the backlight of the buttons on Xiaomi.
⚠️ Warning: Don't believe the "advisers" who recommend that you heat your phone with a hair dryer or knock on the body to wake up LEDs, which can damage the screen or battery, or the backlight is either software-enabled or requires repair.
Myth 1: “Back-lighting drains the battery 30% faster.”
Reality: Even when running continuously, LEDs consume no more than 5-7 mA per hour, which is equivalent to 1-2% of the charge in 8 hours of active use, much more energy is spent on the screen or mobile data.
Myth 2: “On the Redmi 4X, the backlight only works on Chinese firmware.”
Reality: It's not. The backlighting is based on the MIUI version, not the region of the firmware. For example, MIUI 9.5 and MIUI 10 have both global and Chinese builds.
Myth 3: “If the backlight doesn’t turn on, the phone is defective.”
Reality: In 95% of cases, it's a software problem, not a defect, and even if the backlight hasn't worked since you bought it, you can activate it through an engineering menu or firmware.