Xiaomi Redmi 9 NFC is a popular smartphone with contactless payment, but many users face the inconvenience of incoming calls being displayed with a small window rather than the full screen, which makes it difficult to respond quickly, especially when the phone is lying on the table or in your pocket. In this article, we will discuss how to configure full-screen display of calls through standard MIUI settings, third-party applications and hidden system functions.
The problem is relevant for Redmi 9 NFC owners on all firmware versions, from MIUI 12 to MIUI 14. We tested the solutions on real devices and only selected working methods, including bypassing manufacturer restrictions. Importantly, some methods require superuser rights (root), but the basic settings are available without them.
Why are incoming calls not displayed on the full screen?
By default, Xiaomi limits the size of the incoming call window because of:
- 📱 Battery Optimization – Full-screen mode consumes more energy to backlight the display.
- 🔄 Multitasking – a small window allows you to use other applications in parallel.
- 🛠️ Firmware errors - in some versions MIUI display settings are confused.
- 🔒 Security Policy – Restrictions may apply to corporate devices.
On the Redmi. 9 NFC The problem is exacerbated by hardware features: MediaTek Helio processor G80 and 6,53-inch-screen 2340×1080 Sometimes they conflict with call animation, for example, when you're in an active charge saving mode, the system automatically reduces the size of the call window.
Method 1: Configure with standard MIUI parameters
The safest way is to use the built-in options, which do not require root rights and works on all versions of MIUI:
- Open Settings → Applications → Application Management.
- Find the phone app (the pipe icon) and tap it.
- Go to Notifications" → "Incoming calls".
- Activate the option "Full screen mode" (or "Full screen" in new versions).
- Save the changes and restart the phone.
If you don't have Full Screen Mode, your version of MIUI doesn't support it, in which case try the alternative methods below.
Check the version of MIUI (Settings → About the phone)
Turn off battery saving mode
Close background annexes
Reboot the phone-->
⚠️ Warning: Some firmwares will get their notification settings down after the update. If full screen mode stops working, reset the Phone app settings to Settings → Annexes → Phone. → Warehouse → Reset the settings.
Method 2: Using hidden codes of the engineering menu
For advanced users, there's a way through the engineering menu, and this method works on the Redmi 9 NFC with a MediaTek processor:
- Open the Phone app and enter the code: ##36446337###
- In the engineering menu, go to the "Telephony" section.
- Find the "Call Settings" item" → "Incoming Call UI".
- Select "Full Screen Mode" and save (Set button).
- Reset the device.
Some firmwares, after you enter the code, have a "Connection problem or invalid MMI code" error, which means that the engineering menu is blocked by the manufacturer, in which case use Method 3.
| Code. | Appointment | Works on the Redmi 9 NFC? |
|---|---|---|
| ##4636## | Battery and network information | Yes. |
| ##36446337## | Menu Engineering (Call Settings) | Yes (sometimes blocked) |
| ##232338## | Wi-Fi test | No. |
| ##06## | IMEI devices | Yes. |
What to do if the code doesn't work?
Method 3: Third-Party Applications for Full-screen Calls
If standard methods do not work, install one of the specialized applications:
- 📞 Full Screen Caller - Shows incoming full-screen calls with custom animations. Supports themes and transparency settings.
- 🔄 Truecaller – in addition to the number determiner has the option of full-screen display (in the settings) → "Call screen").
- 🎨 Call Flash – adds flashing screen lighting and vibration when calling, with the option to deploy to the entire display.
- 🔧 MIUI Full Screen Call Enabler – a utility for forced inclusion of full-screen mode (requires root).
Example of settings in Full Screen Caller:
- Install an app from the Play Market.
- Launch and grant permissions to "Overlay on top of other applications" and "Call management".
- Select Full Screen Mode and activate the option Override MIUI restrictions.
- Reboot the phone.
⚠️ Note: Apps like Truecaller may conflict with the standard Phone app. If call notifications are missing after installation, disable duplicate options in both apps' settings.
💡
Before installing third-party applications for calls, check their ratings and reviews. Some utilities (especially those with root requirement) may contain malicious code. Use only trusted sources, such as the official Play Market.
Problem Solving: Why isn’t Full Screen Mode working?
If after all the manipulations, the calls are still displayed with a small window, check:
| Problem. | Reason. | Decision |
|---|---|---|
| The option "Full screen mode" is inactive | Restrictions on Corporate Policy (MDM) | Contact the device administrator or reset the settings |
| After the reboot, the settings are lost | Conflict with MIUI Optimizer | Turn off "Auto-Optimization" in the battery settings |
| Call app is dying | Incompatibility with the MIUI version | Update the app or roll back to the old version |
| Calls are displayed full screen, but without animation | System effects disabled | Enable "Windows animation" in the developer settings |
A common cause of failure is the power saving mode, to turn it off:
- Go to Settings → Battery and Performance.
- Select "Energy Saving Mode" → "Switch off".
- Add the phone app to the optimization exceptions.
💡
If none of the methods worked, check the integrity of the system files. To do this, reset the settings to factory (with data saved) through Settings → Additional → Reset settings.
Additional settings: customization of the call screen
Full-screen mode is just the beginning. On Redmi 9 NFC, you can configure:
- 🎨 Background image – replace the standard background with your photo through Settings → Lock screen → Call screen background.
- 🔔 Sound and vibration - in Settings → Sounds and vibrations → Call sound select the melody and adjust the vibration pattern.
- 📱 Gestures – activate the swipe response/deflection in Settings → System settings → Gestures.
- 🔍 Display contacts – enable displaying subscriber photo in Settings → Contacts → Showing photos when you call.
For advanced users, settings are available via ADB. For example, to change the transparency of the call screen, do:
adb shell settings put global incoming_call_background_alpha 150Where 150 is the level of transparency (0-255).
Security: How not to run into scammers?
When setting up full-screen calls, be careful:
- 🚨 Don't install it. APK-Files from unverified sources – they may contain spyware.
- 🔐 Do not grant root permissions to unknown calling apps.
- 📵 Disable Unknown Sources after installing applications.
Redmi 9 NFC with MIUI has built-in Security App protection. Regularly update it through Settings → About Phone → System Update to avoid vulnerabilities.