How to check Xiaomi Redmi 4 for originality and serviceability: a step-by-step guide

Xiaomi Redmi 4 (codenamed prada) remains a popular choice in the aftermarket due to its balance of price, performance and reliability. However, when buying a used device, the risk of a fake "gray" import or a device with hidden defects is extremely high.

We will analyze not only standard checks (appearance, performance of buttons), but also unique for Redmi. 4 nuances - from checking the originality of the firmware to testing specific "diseases" model (for example, problems with the Wi-Fi module on some revisions). 4 Standard (3/32 GB), Redmi 4 Prime (3/32 GB full HD-display) and Redmi 4 Pro (4/64 GB).

1. Originality Check: How to distinguish a fake

Redmi 4 fakes are less common than Xiaomi’s flagship models, but they do exist, with the main features of a clone being poor-quality plastic, technical mismatches and a “curve” firmware.

• 🔍 The Mi logo on the back should be clear, without blurring or uneven edges.
• 📦 The box must have a holographic sticker with IMEI, The fakes are often matte or easily detached.
• 🔧 Screws in the slot SIM-maps - in the original 2 (Redmi 4 Pro — 1 screw + Clones often have a latch. 3-4 squirrels or crosses instead of star-shaped.

The most reliable way is to check the IMEI. Enter *#06#, Write down the number and check it on the official Xiaomi website (mi.com/global/verify). If the site gives an error or the data does not match the box, before you 100% Notice that some fraudsters are counterfeiting and IMEI, So check the serial number on the sticker under the battery (if the phone is collapsible).

⚠️ Attention: AliExpress and other sites often sell replicas of Redmi 4 branded Doogee or Ulefone with similar designs. They are visually similar but have a weak processor and camera. IMEI pre-purchase!

2.Display diagnostics: dead pixels, backlight, sensor

Redmi screen 4 — One of the most vulnerable areas, especially in the IPS-matrix 720p (Redmi's standard. 4 Prime/Pro (Full HD) It's better than the matrix, but it's also subject to wear:

1. Run a video with a uniform color (e.g. black, red, green) on YouTube or use the Screen Test app. The broken pixels will be visible as colored dots.
2. Backlight check. Turn on white background at maximum brightness in a dark room. Yellow spots or uneven backlights (especially at the edges) indicate degradation. LED-lighting.
3. Sensor test. Swipe your finger around the edges of the screen — delays or "missing" touches indicate damage to the digitizer. Use the Touch Screen Test from the Play Market to verify the accuracy.

Pay particular attention to the “yellow hue effect” – a common problem in Redmi. 4 after 2-3 If the screen has a noticeable yellowish tint even with the correct color settings (Settings) → Display. → Color mode, which is a sign of aging in the matrix, can only be corrected by replacing the screen.

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If the seller refuses to test the phone in front of you or turns it on with the video / game already running, this is a reason to be wary.

3. Battery testing: how to find out the real wear

Redmi 4 equipped with a non-removable battery 4100 mAh (at Standard) or 4000 mAhh Prime/Pro). And over time, the capacity drops, and the phone starts to run out in a few hours, and you can check the wear of the battery in a number of ways:

• 📊 Enter ##4636##, select Battery Information. Level indicates current charge and health indicates state (ideal Good).
• 🔋 AccuBattery app. Launch it. 2-3 Charging/discharge cycles -- the program will show the actual capacity. 3000 Mach, it's time to change the battery.
• ⚡ Heat test. Connect the charger and play a heavy game for 15 minutes. If the case heats up above 45.°C (can be checked by an infrared thermometer or appendix) AIDA64) — This is a sign of battery degradation.

Notice the bloating of the battery.

- the screen "raised" at the edges (especially noticeable if you put the phone on a flat surface and sway);

- the back cover extends in the area of the cell;

- The phone doesn't sit flat on the table, it's swaying.

If at least one of the signs is present - it is absolutely impossible to buy such a device: a bloated battery can damage the motherboard.

⚠️ Warning: Some vendors drop charging cycle meters through an engineering menu to hide battery wear. Always check capacity by independent methods (e.g. AccuBattery) rather than trust the data from the Settings → Battery.

View the date of battery production (on the sticker under the lid)|Check the capacity in AccuBattery|Heating test under load|Check the hull for bloating|Make sure the phone is on the table.-->

4. Performance and “iron” check

Redmi 4 It is based on Qualcomm Snapdragon processor 430/435 (Depending on the modification) and Adreno graphics 505. Over time, performance may fall due to wear and tear of flash memory or overheating:

1. Benchmark. Install AnTuTu Benchmark or Geekbench 5. For Redmi 4 Standard, the normal score is 40,000-45,000 on AnTuTu. If below 35,000, there may be problems with the chipset or memory.
2. Stability test, run it. CPU Throttling Test (available on Play Market) If the CPU frequency drops below 1.2GHz when loaded, it's a sign of thermal throttling).
3. Memory check. AIDA64 If Internal Storage shows less than 29 GB (for 32 GB models), it may be that some of the memory is occupied by system debris or the phone has been "remarked" (a common sign of "gray" imports).

Be sure to check the Wi-Fi module - Redmi 4 (especially early revisions) had a problem with the antenna break when falling.

1. Connect to the router in another room.
2. Run WiFi Analyzer and check the signal level (should be no lower than the signal level). -60 dBm).
3. Restart your phone – if Wi-Fi doesn’t automatically connect after a restart, it’s a sign of module problems.

5. Camera diagnostics: not just megapixels

Redmi 4 equipped with a primary camera on 13 MP (at Standard) or 16 MP (y Pro) with aperture f/2.0. However, the actual quality depends on the condition of the module and the firmware:

• 📸 Focus. Point the camera at close range (10-15 cm) If autofocus floats or can't focus, there's a problem with the module or plume.
• 🌓 Quality in the dark. Take a low-light photo. The original Redmi 4 should be night mode (unless the firmware is changed). If the shots are too noisy or green, a matrix defect is possible.
• 🔄 Switch cameras. Switch between the main and front cameras quickly. Delays of more than 1-2 seconds indicate problems with drivers or hardware.

Notice the "artifacts" -- stripes, stains, or color distortions -- that can come from:

- damage to the camera plume (often after falls);

- degradation of the matrix (natural wear);

- non-original firmware (for example, ported from another Xiaomi model).

For accurate checks, install a Camera. MX Open Camera – these applications show a “referred” image without processing MIUI, which helps to identify defects.

6. Check connectors, speakers and microphones

Redmi 4 often wears out physical connectors due to heavy use, and you can check them without special tools:

• 🔌 USB-Type C. Connect the charger and slightly move the cable in different directions. If the charging is interrupted, the connector is shattered. Also check the data transfer (plug into the PC).
• 🎧 3.5mm audio jack, put your headphones in and check the sound in both channels, and if one channel is quieter or missing, there's a problem with the connector or the plume.
• 🔊 Speakers. Turn on the music at maximum volume. Wheezing or distortion indicates membrane damage. Redmi 4 has two speakers: primary (bottom) and conversational (top).
• 🎤 Microphones. Record your voice on a tape recorder and listen. Background noise or muffled sound is a sign of clogging or damage to the microphone.

Pay special attention to the vibration motor. Redmi 4 often fails after moisture is injected. Check it out easily: turn on silent mode and call the phone - the vibration should be smooth, without "twitching".

⚠️ Warning: If a vendor says that a USB-Type C connector "sometimes doesn't work, but if you hold the cable at an angle, it charges" - this is a sign of imminent failure. Repair of the connector on Redmi 4 costs 30-50% of the cost of the phone in the secondary market.

7. Firmware and lock checks

Xiaomi Redmi 4 is often sold with unoriginal firmware, which can lead to problems with updates, sensors or even locking the device.

1. Version. MIUI. Go to Settings. → The phone. → Version. MIUI. The latest official version for Redmi 4 — MIUI 12.5 (based on Android 7.1) If you have a newer version, for example, MIUI 14) is a custom firmware.
2. Loader status. Enter the Service info command in the engineering menu (#7378423##) → If Bootloader shows Unlocked, the phone is unlocked, which could be a sign of a "gray" import or attempted circumvention of activation.
3. Link to your Mi Account. Go to Settings → Accounts. → If the phone requires login/password input when reset, it is tied to someone else's account. Unlocking can cost up to 50% of the device's cost.

If the phone was purchased abroad (e.g. in China), check the regional reference.

1. Install AIDA64.
2. Go to section. CSC (or).
3. If the Sales Code line is specified CN (China), IN (India) or RU (Russia: the phone for this market. CN There are often restrictions (e.g. no Google Play).

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If the phone is tied to someone else’s Mi Account and the seller can’t untie it with you, drop the purchase. Unlocking through official Xiaomi channels can take up to 30 days and requires proof of the original owner’s documents.

8. Check for hidden defects: moisture, falls, repairs

Even if the phone looks perfect, it could have been repaired or contacted with moisture.

• 💧 On Redmi 4, they're located under the lid. SIM-Lot (white or red circle); - under the battery (if the phone is collapsible); If the indicator turned red, the phone contacted moisture.
• 🛠️ Check the screws on the back cover, if they're scratched or have screwdriver marks, the phone's been opened, and check if the lid fits evenly (uneven gaps indicate replacement).
• 📡 The Redmi 4's antenna lines have two plastic inserts on the back, and if they're scratched or painted, the phone falls or gets repaired.

For a deep inspection, use AIDA64:

1. Go to Sensors.
2. Look at uptime, if it's reset every day, you might have a problem with your diet or your diet. BIOS.
3. Check the battery temperature in standby mode if it's above 35.°C is a sign of degradation or background processes.

If the seller claims that the phone "never fell or drowned," ask to show:

- history of repairs (if there are checks);

- the original box with seals;

- all accessories (charging, cable, documentation).

⚠️ Attention: Redmi 4 often changes the battery to the original. To check this, open the back cover (if the phone is collapsible) and look at the battery sticker. MDY-08-EH (4100 mAh) and production date: If the sticker is missing or re-adhesive, the battery is replaced.

FAQ: Frequent questions about Xiaomi Redmi checkout 4