Xiaomi Redmi 4X (The codename santoni remains a popular budget smartphone even years after its release, and one of the most common problems with this model is that it fails to respond to touch, glimpses when pressed, or fails completely after falling. In the service center for the replacement will take from 2,500 to 4000 rubles, but with the tools and patience, the procedure can be carried out independently.
This article is not just a retelling of the general principles of repair, but a detailed guide taking into account the specifics of Redmi. 4X. We will understand how to distinguish sensor malfunction from motherboard problems, what parts to buy (and where not to run into a fake), and also show a unique way to check the sensor plume without a soldering iron - this will save time if the problem is not in the screen. For beginners, we will give a checklist of tools, and for experienced ones, a table of compatibility of spare parts with other Xiaomi models.
How to tell if the sensor is broken
Before you disassemble the phone, make sure that the problem is in the touch layer, not a software failure or damage to the motherboard.
- 📱 The screen is turned on, the image is, but the touches are not recorded (or react chaotically).
- 🔄 The sensor works partially: for example, the upper half of the screen does not respond, and the lower half does not respond.
- 💥 After a fall or impact, “dead zones” appear – areas where touching is ignored.
- 🔌 When connected to a PC, the phone is detected, but it is impossible to control it through the sensor.
If the screen is completely black (no backlighting), the problem may be in the LED-It's not going to help you to change the sensor, the display plume, or the motherboard.
Quick test: connect your phone to charge, if the charge indicator lights up and the screen is black, it's not the sensor that's the problem, and if the screen turns on but doesn't respond to touch, move on to replace.
⚠️ Attention: On Redmi 4X Often there is a "false" sensor malfunction due to the oxidation of the contacts of the plume. Before buying a new screen, try to clean the contacts - this can return the functionality of the device.
What parts to buy: original vs. analogues
For Redmi. 4X There are three types of sensor modules available for sale:
- Original (OEM) — Expensive (from 3,000 rubles), but guaranteed compatible: TCL LTD or OFILM.
- High quality copies (e.g. from JDI or BOE). Cost 1,800-2,500 rubles, the characteristics are not inferior to the original.
- Budget replicas (Chinese "no-name"): Price from 1,200 rubles, but can have poor sensitivity or quickly fail.
When choosing, pay attention to:
- 🔍 The marking of the plume - must coincide with the original (SAN-XX-XX for Redmi 4X).
- 📦 Set: the set must be bilateral tape for fastening and protective film.
- 🛡️ Guarantee – Reliable sellers give at least 3 months.
| Type of spare part | Price (rupe) | Pluses | Cons | Where to buy |
|---|---|---|---|---|
| Original (OEM) | 3 000–4 500 | 100% compatibility, long service life | Expensive, hard to find. | eBay, Specialized Service Centers |
| Quality copy (JDI/BOE) | 1 800–2 500 | Good sensitivity, close to the original | You may find defective copies. | AliExpress (shops with a rating of 98%+), I take it, Yula. |
| Budgetary cue | 1 200–1 800 | Low price, quick delivery | Poor sensitivity, rapid wear and tear | AliExpress, Wildberries |
Tip: If you buy on AliExpress, look for sellers with reviews, where there is a photo of the installed screen on Redmi 4X. The description often says “compatible with Redmi”. 4/4A/4X», In practice, there may be problems with calibration.
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Before buying, ask the seller for a photo of the screen plume - the original must have an inscription. SAN-XX-XX (where XX — This will protect you from buying incompatible parts.
Replacement tools: what you will need
For the Redmi disassembly 4X And you need a minimal set of tools to replace the sensor, and don't skimp on quality, because cheap plastic blades break down and can scratch the body.
Screen suction cup (∅ 5-7 cm)|Set of mediators (plastic/metal blades)|Screwdriver. T3 (torx for screws|Tweezers with curved ends|Dryer or thermo-air station (power 300-500 W)|Double-sided scotch (3M or similar)|Alcohol (isopropyl 90%+) and cotton-stick|Multimeter (to check plumes)-->
In addition, the following may be useful:
- 🧲 Magnetic mat - so as not to lose cogs.
- 🔥 Thermoclei - if you plan to fasten the plume more reliably.
- 📏 Plastic card - for careful screen tweaking.
If you’re disassembling your phone for the first time, practice on an unnecessary device or watch Redmi’s video disassembly. 4X You can take a special note of the moment the battery plume is disconnected, and it's easy to break!
⚠️ Warning: Do not use metal blades without insulation - they can close contacts on the motherboard. If there is no special tool, wrap the tip of the shoulder blade with insulation.
Phone Preparation: Contact Cleaning and Testing
Before replacing the sensor, follow these steps to avoid wasting money on parts:
- Reset settings through Settings → Additionally. → Recovery and reset: Sometimes the sensor freezes because of a software failure.
- Check the plume: Remove the back cover (suction and shoulder blade). Turn off the battery (gently pluck the power plume). Check the contacts of the touch plume on the motherboard - if there is oxidation, clean them with alcohol and eraser.
Test without a screen
- Connect the phone to the charger.
- If the charging indicator is on and the screen does not respond, the problem is precisely in the sensor or its plume.
Unique life hack for Redmi 4X: If the sensor is working but it's floating (touching is not where you're pressing), try flashing the phone with a Fastboot. Sometimes this solves the problem without changing the screen:
fastboot flash touch touch_santoni.img
fastboot rebootFile. touch_santoni.img can be found on the forums 4PDA or XDA Developers.
How to check the sensor plume with a multimeter?
Step-by-step replacement of the touch screen
Now, to the replacement itself. Follow the instructions carefully. 4X It has fragile plumes that are easy to break.
Step 1: Disassembling the phone
1. Turn off the phone and remove SIM-memory-card.
2. heat the screen edge with a hair dryer (temperature 60–80)°C) for 2-3 minutes - this will soften the glue.
3. Suction the screen from either side, then gently slap it with a spatula. Don't pull too hard, there are plumes under the screen!
4. Disconnect the plumes:
- Touch (top, wide).
- Display (bottom, narrow).
- The tail of the Home button (if any).
Step 2: Remove the old sensor
1. Remove the metal frame that attaches the screen to the body (unscrew 4 screws) T3).
2. Carefully separate the touch layer from the display.They are glued together, so use a plastic card and a hair dryer (heat to 50)°C).
3. Remove the remnants of bilateral tape from the phone frame with alcohol.
Step 3: Installation of a new sensor
1. glue the new sensor to the display (if purchased separately) or use the finished module.
2. Connect the plumes in reverse order:
- First, the display (narrow).
- Then sensory (broad).
The last thing is the Home button (if it was removed).
3. Secure the screen on double-sided tape, press and warm up with a hair dryer (40)°C) for better adhesion.
Step 4: Assembly and testing
1. Make sure all plumes are tightly connected.
2. Turn on the phone and check:
- Does the sensor respond to touches throughout the area?
- There are no dead zones.
Does the Home button work properly (if it is physical)?
3 If everything works, tighten the screws and seal the body.
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The most common mistake when replacing the sensor with Redmi 4X — If the screen doesn't work after assembly, take the phone apart and check the contacts again.
Frequent Mistakes and How to Avoid Them
Even experienced craftsmen sometimes make mistakes when replacing the sensor with a Redmi. 4X. Here are the most common:
- 🔌 Damage to the battery plume -- it goes over the motherboard and it breaks easily. Always turn it off first!
- 🔥 Overheating of the screen with a hairdryer - if the temperature is above 90°C, you can damage the liquid crystal layer. Keep the hair dryer at a distance of 5-10 cm.
- 🧲 Loss of screws - at Redmi 4X There are only 4 of them, but they're very easy to lose.
- 📱 Incompatible sensor - even if the screen looks good, the plume may not connect!
If the sensor is working after the replacement, but the image on the screen is distorted (strips, broken pixels), the problem is in the display plume or the display itself. + sensor).
⚠️ Attention: On Redmi 4X firmware MIUI 12+ After the sensor is replaced, you may need to calibrate. → The phone. → All parameters. → Sensor calibration (if no item, use the engineering menu: ##6484##).
Where is cheaper: self-replacement vs. service center
The cost of replacing the sensor in the service depends on the region and the status of the workshop.
| Type of service | Cost of work (ruble) | Cost of spare part (ruble) | Total (rupe) | Guarantee |
|---|---|---|---|---|
| Official Xiaomi service | 3 500–4 500 | 3,000–4,000 (original) | 6 500–8 500 | 6–12 months |
| Local workshop | 1 500–2 500 | 1,800–2,500 (copy) | 3 300–5 000 | 3–6 months |
| Self-sustaining replacement | 0 | 1 200–3 000 | 1 200–3 000 | Depends on the store. |
Self-replacement is 50 to 70 percent better, but only if you already have tools, and if you buy them from scratch, you'll save 20 to 30 percent, but the experience you get from repairing them will be useful for other devices.
When you should not repair yourself:
- 🔧 If the phone is warranty (self-repair cancels it).
- 💻 If there are other breakdowns in addition to the sensor (for example, the camera or speaker is not working).
- ⚡ If you have never held a soldering iron or multimeter in your hands.