If you’ve encountered the Xiaomi MCT3B acronym in documentation, on the box, or in the settings of your TV, but you can’t figure out which model it’s talking about – this article is for you. The manufacturer often uses internal codes to designate series and modifications, which causes confusion among users. MCT3B is not the name of a particular model, but part of a cipher that helps determine the line, diagonal and even the year of the TV.
In this article, we will explain which Xiaomi TVs are hidden under the MCT3B marker, how to decrypt this code, and why it is important when choosing firmware, accessories or repairs. You will also learn how to distinguish Mi TV 4S from Mi TV 4A from this code, and what to do if your device has a different cipher – for example, MCT2B or MCT4C. Detailed tables, photo examples and step-by-step instructions will help avoid errors.
What does the MCT3B code mean in the Xiaomi model?
The acronym MCT3B is the internal designation of the Xiaomi TV platform, which consists of several parts:
- 🔹 MC — prefix denoting the Mi line TV (also MD for Mi TV Stick or MA audio-devices).
- 🔹 T is a letter indicating the type of screen: T — LED-lighting (most models), O — OLED (rarely, Q — QLED (premium series).
- 🔹 3 is a number indicating the platform generation or release year (e.g., 3 often corresponds to 2019–2020 years).
- 🔹 B is a suffix indicating modification (may be A, B, C, etc.).
Thus, MCT3B — It's a platform for LED-Xiaomi 3rd generation TVs released between 2019 and 2021, but this code is not the full name of the model. TV 4S 55" MCT3B or Mi TV 4A 43" MCT3B.
What Xiaomi models are related to the MCT3B platform?
The MCT3B code is found in several popular Xiaomi TV series, and below is a table with the main models, their diagonals and key features:
| Model | Diagonal | Permission | Features | Year of release |
|---|---|---|---|---|
| Mi TV 4S | 43", 50", 55", 65" | 4K UHD (3840×2160) | HDR10, Dolby Audio, PatchWall | 2019–2020 |
| Mi TV 4A | 32", 40", 43", 50" | Full HD (1920×1080) | Budget series, 60 Hz, no HDR | 2019–2021 |
| Mi TV 4X | 55", 65" | 4K UHD | MEMS 120 Hz, Dolby Vision, metal body | 2020 |
| Mi TV 4 Pro | 55", 65" | 4K UHD | AMLogic T972, 2 GB of RAM, voice remote | 2019 |
Important: TVs with MCT3B code do not support upgrading to MIUI TV 3.0 and later – the maximum firmware version for them is limited to MIUI TV 2.5. This means that some new features (such as integration with Xiaomi Home or low latency game mode) may not be available.
If your TV has an MCT3B code but the model doesn’t match the table above, check the sticker on the back – it may have a full article, such as L43M6-6ASR (for Mi TV 4A 43) or L55M6-5ASR (for Mi TV 4S 55).
How to find out the exact model of your Xiaomi TV?
If you’re not sure what your TV is, there are a few ways to find out:
- 📺 Through the Settings menu: Go to Settings → On TV. → Model. It'll have the full name, for example, Mi. TV 4S 55" type-article MCT3B-L55M6-5ASR.
- 🏷️ On the back of the TV (usually at the bottom) there is a sticker with the serial number and the code of the model: L55M6-5ASR or MCT3B-....
- 📦 Box: The original package always shows the model and diagonal. Note the barcode, which may contain information about the modification.
Examine the sticker on the back panel|Check the "About TV" section in the settings|Compare the data with the model table MCT3B|Clarify the diagonal on the documents-->
⚠️ Note: Some sellers only specify the platform code in the description (e.g, MCT3B), but don't specify the series (4S, 4A This can lead to the purchase of a TV with unexpected characteristics (e.g. Full). HD instead 4K). Always check the full name of the model!
Differences between MCT3B and other Xiaomi platforms (MCT2B, MCT4C, etc.)
Xiaomi platform codes evolve with the hardware, and the key differences between the popular versions are as follows:
- 🔧 MCT2B: Older models (2017–2018), Amlogic 905 processors, 2GB of RAM maximum, no Dolby Vision support. TV 4 55” (first generation).
- 🔧 MCT3B: Platform 2019–2020 CPUs, Amlogic processors T962/T972, before 2.5 GB RAM, support HDR10 Dolby Audio, the most widely used series.
- 🔧 MCT4C: New models (2021–2022 (d.), MediaTek processors MT9611/MT9638, before 3 GB RAM, support for Dolby Vision and MEMC 120 Hz. Examples: Mi TV Q2 55".
- 🔧 MCT5A: Premium TVs 2022-2023 (e.g. Xiaomi) TV 6 OLED), MediaTek processors MT9950, 3 GB of RAM, QLED-screen.
If you plan to upgrade your firmware or buy accessories (such as bracket mounts), the platform code is critical. For example, MCT3B remotes are not always compatible with MCT4C, and firmware for different platforms can lead to a device "brick".
What happens if you flash MCT3B with MCT4C firmware?
Where the MCT3B code is used: firmware, repair, accessories
Knowledge of the MCT3B platform code is useful in several situations:
- 🔄 Firmware Update: Firmware Files for Xiaomi TV This is often referred to as a platform, for example: mct3b_user_2.5.10.zip. You need to download the version that corresponds to your code!
- 🛠️ Repair and replacement of parts: When buying a motherboard, power supply or matrix, sellers request a platform code. MCT3B-L55M6-5ASR not fit for MCT4C-L55M7-7ASR.
- 🎮 Peripheral connectivity: Some game controllers or sound bars (e.g., Xiaomi Soundbar) have limited compatibility with certain platforms.
⚠️ Note: When ordering spare parts on AliExpress or other sites, specify not only the code MCT3B, but also the full article (e.g, L55M6-5ASR). Details for Mi TV 4S 55" mi TV 4A 55" (both MCT3B) differ!
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Before buying firmware or spare parts, check the serial number of the TV in the official Xiaomi service at the link: https://www.mi.com/global/verify.
Frequent problems with MCT3B TVs
TVs with MCT3B code, despite their reliability, have a number of common problems:
- 🔌 Spontaneous reboots: Often associated with overheating of the power supply or failure of the capacitors.The solution is to replace the PD or improve ventilation.
- 📶 Wi-Fi problems: Module AP6256 (meet MCT3B) It can lose connection. It helps to reset the network or the firmware module.
- 🔊 Sound distortion: In Dolby Audio models, sometimes the sound "hrills" at high volume. TAS5756M.
- 🖥️ Artifacts on screen: Vertical stripes or flickering indicate problems with the T-CON plate-line.
If your Xiaomi MCT3B TV is slowing down, try the following steps:
1. Reset settings: Settings → All settings → Restore and reset → Reset settings.
2. Clear the cache: Settings → Applications → Delete data for "PatchWall" and "Launcher".
3. Update the firmware: Settings → About TV → System Update (use only official files!).💡
Most MCT3B problems are solved by flashing or replacing the power supply. If the TV doesn't turn on after the upgrade, try rolling back to the previous version of the software via USB.