Replacement of light bulbs in the Xiaomi TV: disassembly, diagnosis and installation of new LEDs

Replacing the backlight bulbs in a Xiaomi TV is a challenge that every LED-TB owner over the age of 3-4 will face sooner or later. Dim screen, uneven brightness or complete absence of image when the sound is working are symptoms of LED backlight failure. Unlike replacing the matrix, which requires professional skills, you can change the lamps yourself, saving up to 70% of the cost of repair in the service center.

In this article, we will analyze the process from fault diagnosis to check the health after replacement, taking into account the features of popular Mi models. TV 4S/4A/5 Pro and Redmi Smart TV. You will learn what tools you will need, how to avoid typical errors (for example, damage to plumes or overheating of the matrix), and where to buy high-quality products. LED-And we'll focus on the difference between replacing individual diodes and whole backlights, which is a fundamental factor that affects the complexity of repairs and the cost of repairs.

Signs of malfunctioning light bulbs in Xiaomi TV

The first step is to determine that the problem is in the backlight, not the matrix, power supply or mainboard, and here are the key symptoms:

• 🔦 The screen is dim, but you can see it in bright light -- a classic sign of partial light output. Try flashing a flashlight at an angle, if it shows up, it's the backlight.
• 🌑 Black screen, but the sound works – most often it is a complete failure LED-Check if the power indicator is blinking in non-standard mode (for example, 3 times in a row).
• 🟥 Spots or stripes on the screen – if they are static and independent of content, they may be burnt out diodes in specific backlight areas.
• 🔥 The television is spontaneously turned off through 5-10 minutes – sometimes due to overheating due to faulty lamps (especially relevant for models with passive cooling).

For accurate diagnosis, use the light test:

1. Turn on the TV and wait for the Xiaomi logo to appear (if the screen is completely black, wait 1-2 minutes).
2. Light a flashlight from 5-10 cm at right angles. If you see a faded image, the backlight doesn't work.
3. Try running the Service Menu (to do this, press Menu → Settings → All settings → Device → OK button 5 times). From the menu, select LED Test - if the screen remains dark, the problem is with the lamps or their driver.

⚠️ Warning: If the Xiaomi TV doesn't respond to the remote and buttons on the body, don't rush to disassemble it - check the power supply first. TV 4S 55" and Redmi X50 frequently fails the condenser C901 (1000 μF, 16V – its replacement can return the backlight without disassembling the screen.

What light bulbs are used in Xiaomi TVs

Xiaomi TVs use two types of backlighting:

To replace it, it is important to know the exact parameters of the lamps of your model.

• 📄 On the back of the TV (look for the labels) LED Type or Backlight Model).
• 🔍 In the service menu: Settings → All settings → About the device → Information on the LCD panel.
• 🛒 On parts seller sites (such as AliExpress or eBay) – type in a TV model +"LED backlight strip".

The most common lamps for Xiaomi:

• For Mi TV 4A/4S: 2835 SMD (12V, 30-60 diodes per meter) tapes.

⚠️ Attention: In Xiaomi models 2022 years and later (e.g. Mi) TV 6) They use custom diode addressing tapes for local dimming, and their replacement requires software calibration through Xiaomi service software. TV Assistant! 📊 What is the Xiaomi model? TV You have it? TV 4A/4SMi TV 5 ProRedmi Smart TVMi TV 6Other model Tools and materials You will need to replace the light bulbs: Torx screwdriver T5/T6 (for the back cover) Plastic mediators (for parsing the frame) soldering iron 30-60Watt + solder/flux (if you solder diodes) Multimeter (to check the voltage on the driver) Thermoclei or double-sided tape (for fixing tapes) Antistatic bracelet (required for matrixes) 55" and more) Backlight lamp (original or analogue with the same parameters)--> Where to buy spare parts: 🛒 AliExpress – Cheap Analogues (Look for Sellers with a Rating) 98%+ Compatibility with Xiaomi). 🏬 Local service centers are original tapes, but more expensive in the 2-3 once. 🔧 Radio markets – suitable if you need separate diodes 2835/3014 - Replacement cost: 💰 Independently: 1 500–4 000 ₽ (ribbon + tool). 💼 On the service: 5 000–12 000 ₽ (If you've never soldered chips, you'd better buy ready-made tapes with connectors -- you just need to plug them into the driver without soldering. TV 5 Pro and newer note the tapes labeled Xiaomi Original — they come with pre-configured resistors to work correctly with the native driver. Step-by-step instructions for replacing the lighting lamps Replacement process will be analyzed with the example of Mi TV 4S 55" (Similar to most Direct models LED). For Edge. LED Full-Array nuances will be described separately. 1. Disconnect and disassembly of the TV Before work: Turn off the TV from the socket and wait for the discharge of the capacitors (minimum) 10 Remove the stand (if any) - it usually attaches. 4 Torx screw T20. Place the TV screen down on a soft surface (like a blanket).Next: Remove the back cover by unscrewing all Torx screws T5/T6 Disconnect all the plumes from the mainboard and the power supply (remember their location or take a picture!) Carefully remove the metal frame holding the matrix (it is attached to the latches - use plastic mediators). ⚠️ Attention: In Mi models TV 5 Pro 65" mi TV 6 75" The matrix is fixed by additional screws under the frame, and if you don't unscrew them, you risk damaging the plumes as you lift the screen! 2. Access to backlight lamps After removing the frame: Lift the matrix vertically (do not disconnect the plumes!) and fix it on the stand. Under the matrix, you'll see an aluminum radiator -- that's the backlight. Unscrew the radiator. T8) And take it down carefully, and it is placed under it. LED-In the Edge models. LED (Like Redmi. X55) The tapes are on the sides of the screen. To get to them, you need to: Remove the front frame (it is held on clips, put it on the mediator from the corner), unpick the light guides (they look like transparent plastic strips), tapes are attached to double-sided tape, they need to be carefully disconnected from the driver. 💡If the tapes are soldered to the driver, do not tear them by force! Warm up the soldering places with a hair dryer for 300°C or soldering iron, and then carefully remove solder vacuum pump. 3. Replace lamps Option 1: Replace the whole tape (easier and more reliable): Disconnect the tape connector from the driver (it can be clip or soldered). Remove the old tape from the radiator (it is attached to heat glue or tape). Install the new tape with the driver connector. Secure it with heat glue. Option 2: Replace individual diodes (cheaper, but requires soldering skills): With a multimeter in vertebrae, find the burned diodes (they will not "ring"). Warm up the defective diode with a hairdryer or soldering iron and remove it. Install the new diode while observing polarity (the anode and cathode are marked on the board). For models with Full-Array (for example, Mi Mi). TV 6): The tapes are arranged in several rows - they need to be replaced with a kit. After replacement, the backlight is calibrated through the service menu (Settings) → For engineers. → LED Calibration). 4. After lamp replacement: Set the radiator in place and secure it with screws. Carefully lower the matrix and frame it. Connect all the plumes and the back cover. Turn on the TV and check the uniformity of the backlight (use the White Screen test mode in the service menu). 💡If after the replacement there are vertical stripes or flickering, check the density of the tapes adjacent to the radiator - overheating of the diodes leads to unstable work. Typical errors and how to avoid them Even experienced craftsmen sometimes make mistakes that lead to re-repair. Here are the most common: 🔌 The wrong connection of the connectors -- if you confuse the polarity, the tapes will burn up immediately when you turn on. +/– board-and-ribbon. 🔥 Overheating in soldering - diodes 2835/3014 Wear a soldering iron less powerful than a heat-sensitive iron. 60Watt and flux without acid. 🧲 Static electricity - it can damage the matrix or mainboard. Always use an antistatic bracelet, especially when working with models 65" more. 📏 The length of the tapes is different, if the new tape is longer than the original, it will warm up and quickly fail! 🔄 Forgot to calibrate backlights in models with Full-Array (for example, Mi). TV 6) after replacement, calibration must be started through the Service menu → LED Adjustment. If the lamps are replaced, the TV will not turn on: Check the fuse on the power supply (often burns out when short). Make sure that all the plumes are connected correctly (especially the matrix plume). Call the multimeter circuit from the light driver to the tapes, maybe a cliff somewhere. What if after the replacement there are spots on the screen? Spots usually arise from the uneven adjoining of the tapes to the radiator. Solution: 1. Take apart the TV and check if the tapes are tightly glued to the radiator (should be without gaps). 2 If you use heat glue, apply it in a thin layer - excess glue can create "air pockets." 3. In models with Edge LED spots may appear due to contamination of light guides - wipe them with alcohol. The quality of the lamps depends not only on the brightness of the screen, but also the life of the TV. Here are the tested options: Source Pros Minuses Average price (per ribbon) Official service centers Xiaomi Guarantee 6-12 months, original details Expensive, long wait (if not available) 3 000–6 000 ₽ AliExpress (sellers: Xiaomi Original Store, TV Parts Pro) Low prices, wide range Risk of running into a fake, long delivery 800–2 500 ₽ Local parts stores (e.g. Chip and Deep) Can be checked before purchase, fast delivery Limited choice, prices higher than on AliExpress 1 500–4 000 ₽ Groups in Telegram (for example, @XiaomiTV_Repair) You can buy used tape in good condition, consultation from masters No guarantee, risk of getting married 500–1 500 ₽ When choosing lamps, pay attention to: 🔦 Brightness (lumens) – must match the original (for example, for Mi). TV 5 Pro - at least 1200 llm). 🔋 Stress - if the original is on 24B, don't take the tape on 12B (she'll burn). 🎨 Color temperature – for Xiaomi, it is common 6500K (cold-white). 📏 Length and number of diodes - even if the tape looks similar, check the number of diodes per meter. TV 6 And look for tapes that are marked Local Dimming, which are zonal dimming-enabled. Normal tapes will work, but the function is HDR Alternative solutions: when replacing the lamps doesn't help If the lamps have a problem after replacing the lamps, another component may have malfunctioned: 🔌 Driver of lighting - in models Mi TV 4A/4S chips often fail BP2832. It'll cost you to replace her. 1 000–1 500 ₽. 🔋 Power supply - if it does not give the desired voltage (for example, 24Instead 48B, the tapes won't light up. Check the multimeter. 📱 Mainboard – if the lighting controller is burned (U301 mi TV 5 Pro), you will need to flash or replace the chip. 🔄 Matrix plumes -- oxidized contacts can mimic a backlight malfunction. Clean them with a smoothie. If you're not sure about the diagnosis, use the component test: Turn off the backlight connector from the driver and turn on the TV. If the screen is black, but there's sound, there's a problem in the driver or mainboard. Check the voltage at the output of the power supply (should match the label on the sticker). If when you turn on the TV clicks the relay in the power supply, but the screen does not light up, most likely the unit itself is defective. T-CON A board or matrix will cost 50-70% of the cost of a new TV, and in such situations, it is more appropriate to consider buying a new model. FAQ: Frequent questions about lamp replacement in Xiaomi TV Can you replace the light bulbs without soldering? Yes, in most Xiaomi models (except Mi). TV (6) the tapes are connected via connectors. You just have to disconnect the old tape and connect the new one, except if the individual diode on the tape burns out, then soldering is necessary. TV? Average service life LED-lamp — 30 000–50 000 hours 5-7 In models with full-Array (e.g. Mi) TV 5 Pro) lamps fail faster due to higher loads. The duration of operation is affected by: frequency of TV on/off, cooling quality (dust on the radiator reduces the life of the system), voltage in the network (voltage surges are harmful to drivers). Can I use lamps from other brands (Samsung, LG) Xiaomi TV? Theoretically, you can, but only if you match: Power voltage. Type of diodes (2835, 3014 Length of tape and number of diodes. However, in models with local dimming (for example, Mi). TV 6) Lamps from other brands will not work properly with the Local Dimming system. What if the screen flickers after replacing the lamps? The flicker is usually caused by: Weak fit of tapes to the radiator (diodes overheat). voltage mismatch (for example, put the tape on the radiator). 12Instead 24B. Bad contact in the driver connector. Solution: take the TV apart, check the tapes and contacts are secure. If there's any flicker left, replace the light driver. Where to find the lamp circuitry for my Xiaomi model TV? Schematics can be found on Elektrotanya or Badcaps (see TV model) or VC or Telegram groups dedicated to Xiaomi repair (e.g., Xiaomi repairs, @XiaomiTV_Service). In the service menu TV: Settings → For engineers. → Connection Scheme (not available on all models). For popular models (Mi TV 4S 55, Mi TV 5 Pro 65), the schemes are often posted on the 4PDA or XDA-Developers forums.