Watching video content on a big screen is always a more immersive experience than on a smartphone display, even if you have a powerful Xiaomi Redmi in your hands. 9S. However, not everyone has stable Wi-Fi or Smart. TV In these situations, a direct wired connection comes to the rescue, which ensures maximum picture quality without delay and compression. USB-cable to connect your phone to your TV allows you to turn your gadget into a full-fledged media center.
Owners of Android devices often face the myth that video transmission via USB is impossible without special docking stations. In fact, modern smartphones, including the Redmi series, have the necessary hardware capabilities for direct image output, the main thing is to set up the interface and choose the right method of data transfer, whether it is a drive mode or a digital video output.
In this guide, we will take a look at the details of how to connect the Xiaomi Redmi 9S to a TV, the technical requirements, step-by-step instructions for setting up the system, and how to solve typical content display problems, and how to make your TV see your phone and play movies in high resolution.
Technical requirements and interface compatibility
Before you start setting up, you need to make sure that your devices are physically compatible. Xiaomi Redmi 9S smartphone has a USB Type-C port that supports the USB 2.0 standard. This means that to transmit a video signal over a digital protocol (MHL or DisplayPort Alt Mode) may require an active adapter, since the native port of the phone does not always produce a video signal without additional processing. However, there is an alternative method of transmitting data when the TV reads files directly.
A key element here is smartphone-side OTG (On-The-Go) support. This feature allows the mobile device to host and power external accessories. In the case of the Redmi 9S, OTG support is built into the MIUI shell by default, but video output often requires a dedicated USB-C to HDMI adapter. If your TV doesn't have Smart features, this adapter will become a bridge between the mobile operating system and the screen.
⚠️ Note: Not all cheap adapters USB-C on HDMI Make sure that the adapter description explicitly includes support for video output for Android, not just charging and transferring data.
It is also important to consider the requirements for the cable itself. For stable data transmission and power, use the original Xiaomi cable or certified analogue labeled 3A or higher. Thin cables for charging headphones may not miss the necessary current, which will lead to permanent screen shutdowns or the inability to identify the device with the TV. Insulation quality and thickness of the lived directly affect signal stability.
Equipment preparation and OTG settings check
The first step in the setup process is to activate the necessary features in the Android system. in most cases, Xiaomi Redmi 9S automatically detects the connection of external devices, but for certainty it is worth checking the status USB-Debugging and port mode. Go to Settings menu, then select About phone and quickly click on version seven times MIUI, activate the developer mode.
Once you activate the hidden menu, go back to the main settings and find the Additional → For Developers section. Here, make sure that the USB Configuration function is set to file transfer mode (MTP) or PTP by default if you plan to transfer photos. For the video output through the adapter, the system should automatically switch to the image output mode as soon as the external display is detected.
☑️ Checking system readiness
Keep in mind the power. When you display the image on the external screen, the power consumption of the Xiaomi Redmi 9S increases significantly. If you use a passive adapter, the phone can quickly run out. It is recommended to connect the charger simultaneously through the second port (if a hub is used), or make sure that the smartphone battery is fully charged before starting to watch a long movie.
Direct Connection Method through USB-cable (Reim drive)
The most versatile way that does not require the purchase of expensive adapters HDMI, — This is using the phone as an external drive. In this scenario, Xiaomi Redmi. 9S plug-in USB-The TV takes the smartphone as a flash drive, allowing you to open files directly through the built-in media player, which is ideal if your TV supports reading exFAT file systems or NTFS.
To implement this method, connect the cable to both devices. On the screen of the smartphone will appear a notification about the mode of operation. USB. Click on it and select File Transfer or Photo Transfer (PTP). Then, on the TV remote, press the signal source selection button (usually labeled Source or Input) and select the appropriate one. USB-The menu of the TV will display the file system of your Redmi. 9S.
| Parameter | The USB Mass Storage (USB Mass Storage) | HDMI mode (Adapter) |
|---|---|---|
| Image quality | Depends on the TV codec. | Native screen resolution |
| Delay. | Minimum | Absent. |
| Management | Remote TV | Phone screen (or remote) |
| Charging. | Battery's running out. | Requires external nutrition |
The main limitation of this method is that video codecs are supported by the TV itself. Built-in players often cannot play modern compression formats such as HEVC (H.265) or audio codecs like DTS. If a file starts with a message "Unsupported format", you will either have to convert the video or use software broadcast methods, which will be discussed below.
Use USB-C to HDMI adapters for mirror display
If your TV doesn’t support the necessary codecs or you want to stream the image from the screen (for example, for games or browsers), you will need an active USB-C to HDMI adapter. Since the Xiaomi Redmi 9S is based on the Snapdragon 720G processor, it does not have native video output support through the port (DisplayPort Alt Mode technology is not available at the hardware level).
When connected via such an adapter, the phone may require confirmation of debugging or image output permission. In some cases, you need to activate the Developer Options mode and enable forced resolution or simulation of the additional screen. Once connected, the TV will determine a new signal source, and the Redmi 9S screen will display a menu for selecting the mode of operation (Translation, Extended Screen or Duplicate).
Why can't the Redmi 9S see an HDMI adapter?
It’s important to consider resolution. Even if the adapter supports 4K, the smartphone itself can limit output to 1080p due to interface bandwidth limitations or MIUI power saving settings. This is enough for watching movies, since most streaming services do not exceed this quality threshold on mobile devices.
Software methods of broadcasting via USB-modem and local network
There is another way that is often ignored: using USB-cable to create a local network between the phone and the TV (if the TV has Smart-functions). USB-modem on Xiaomi Redmi 9S, In this case, the TV will get Internet access through the phone, and you can run a media server on your smartphone (for example, Serviod or built-in player). VLC), which will open access to files over the local network.
This method allows you to use powerful software decoders of a smartphone to process video, transmitting to the TV already finished stream. LAN/SMB enter IP-The address that the server app will give you on the phone, so you're circumventing the limitations of the built-in player on the TV.
⚠️ Attention: When using the mode USB-Make sure you have unlimited rates on or you don't consume mobile traffic. Although the transfer is local, some systems may try to log on to the global network to check. DRM-licensee.
The advantage of this approach is that it's versatile. You don't need special cables. HDMI, standardize USB-And the cord. And it keeps running in the background, allowing you to respond to messages or check social media while the movie is on the big screen. This is especially convenient for Redmi owners. 9S, who value multitasking.
💡
Use the player. VLC for Android with rendering or cast enabled, it can find devices on the local network even when you connect through a network. USB-modem, providing better compatibility with audio and video codecs.
Problem Solving: No sound, black image or desynchronization
Users often face technical difficulties in setting up, and one of the most common problems is that there is no audio track when playing videos successfully, which is because the Xiaomi Redmi 9S can stream videos but not switch audio output to an external channel, and you can solve this by going to Settings → Sound and vibration and by forcibly selecting audio output via HDMI or USB, if this option is available in your version of MIUI.
Another common problem is desynchronization of sound and image, which is typical of software broadcasting methods, where the processor can't handle coding the stream in real time, so try to lower the bitrate of the video or choose a different codec when converting, and it also helps to close all the background applications on the smartphone to free up RAM resources.
If the TV screen is black, even though the phone is showing connectivity, check the resolution. Try changing the screen refresh rate or the developer's resolution. Sometimes it helps to reboot both devices with the cable already connected. Android should re-run the handshake procedure and determine the display settings.
💡
Most of the image output issues on Redmi 9S are solved by upgrading MIUI firmware to the latest version or using external players with their own output drivers, such as the MX Player Pro.
Optimization of reproduction and energy consumption
For long-term movie watching, it's important to minimize energy consumption. The screen of the smartphone is one of the main consumers of energy. HDMI-Adapter is recommended to turn on "Do not turn off screen" only if necessary, but it is better to set up automatic turn off of the display after 30 seconds so that the phone does not overheat.
Also worth paying attention to the file system format. To store movies over 4 GB, use the exFAT file system. Standard FAT32 doesn't support files of this size, and you just won't be able to copy the movie to your phone for later viewing via USB. Xiaomi Redmi 9S works great with exFAT out of the box.
To sum up, the Xiaomi Redmi 9S and USB TV offer a lot of options for home theaters, and the choice of method depends on your goals: for maximum quality and games, an HDMI adapter is better, and for simple viewing of downloaded movies, the drive mode is enough. Experiment with settings, and you will find the optimal balance between quality and convenience.