Replacement of the back cover on Xiaomi Redmi Note 7: a complete analysis with the nuances

Xiaomi Redmi Note 7 is one of the most popular smartphones of 2019, but over time, even its sturdy glass back can crack, peel off or simply get bored with the appearance. Replacing the lid seems like a simple task, but in practice it harbors many pitfalls, from improper selection of glue to damage to camera plumes or fingerprint scanner. In this article, we will analyze all the stages of the process, from choosing a new panel to the final build, with an emphasis on typical errors and professional life hacks.

It's important to understand that Redmi Note 7 (codename lavender) has a unique design: its back cover is glued to a frame, and underneath it hides fragile components — antenna modules, connectors and even part of the cooling system. If you have not previously repaired smartphones, it's better to train on a less valuable device or go to the service. But if you don't hesitate, let's get ready!

Training: tools and materials

Before you take your smartphone apart, make sure you have everything you need, and even missing one tool can cause permanent damage — for example, trying to put a lid on a knife instead of a mediator is almost guaranteed to break the glass or damage the plumes.

Here is the minimum set you will need:

• 🔧 Set of screwdrivers (cross-haul) PH00, flat 1.5 mm, five-pointed Y00 screw-to-speaker)
• 📱 Plastic mediators (2-3 pc, thickness 0.1–0.2 mm) or special blades for disassembling smartphones
• 🔥 Dryer or thermo-air station (at least 1000 W) for softening the adhesive
• 🧴 Adhesives for back covers (recommended) B-7000 or T-7000 — They are flexible and do not damage components)
• 🧊 Isopropyl alcohol 90%+ (for cleaning glue residues and degreasing surfaces)
• 📦 New back cover (original or high-quality analogue with metallized antenna tracks)

Additional accessories will also be useful:

• 🧲 Magnetic substrate or screw container (so as not to lose small parts)
• 🔍 loope USB-microscope (to check antenna contacts and plumes)
• 🧤 Antistatic gloves (protection against static electricity that can damage the motherboard)

⚠️ Note: If you buy a non-original cover, note the presence of metallized antenna tracks on the inside. Cheap fakes often don't have them, which leads to loss of network signal and Wi-Fi after replacement.

Selection of the back cover: original vs analogues

There are three types of back covers for the Redmi Note 7:

1. Original (OEM) - manufactured by Xiaomi, ideally suited in size and have all the necessary antenna elements. minus: high price (from 1500 rubles) and difficulty with search.
2. Quality analogues (for example, from Kwmobile or Olixar) – often do not inferior to the original, but may have slight differences in color shade or texture.
3. Cheap replicas (without a brand, with AliExpress) are a risky option: they may not match the mounts, have curved holes under the camera or the absence of antenna tracks.

How to distinguish a quality cover from a fake?

⚠️ Note: If you buy a lid with already applied glue (so-called "3M-Be careful - this glue is often of poor quality and can fall off after a few days. B-7000.

Step-by-step instructions for dismantling a smartphone

Before you start, completely turn off the smartphone and remove it. SIM-I'd rather work on a clean desk with good lighting.

Turn off the smartphone and remove the tray SIM-cards |

Remove the cover (if any)|

Prepare all instruments |

Check the temperature of the hair dryer (not higher than 80°C for glass)|

Take a picture of the initial state of the lid (for comparison after replacement)-->

Step 1: Heating the lid

Turn the dryer on at medium power (temperature ~70-80°C) and warm the back evenly for 2-3 minutes, paying special attention to the edges. This will soften the glue. Don't overheat one place - the glass may crack!

Step 2: Filting the lid

Insert the plastic mediator into the gap between the lid and the frame (start at the bottom edge where the charging connector is). Carefully drive the mediator along the edge, gradually separating the lid. If you feel resistance, warm up the place again with a hairdryer.

Step 3: Disconnecting the plumes

After removing the cover, you will see:

• 📷 Main camera plume
• 👆 Fingerprint scanner plume (if it is built into the cover)
• 📶 Antenna contacts (do not tear them off by force!)

Carefully unplug all the connectors with a plastic blade.

Step 4: Removing Old Adhesive

Moisten the cotton-coated disc with isopropyl alcohol and thoroughly clean the smartphone frame of glue residues. Do the same with the inside of the new cover (if it has factory glue on it).

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If the glue doesn’t go away, use a wooden stick (like ice cream) – it doesn’t scratch the surface, unlike metal tools.

Installation of a new cover and assembly

Now, the most important step is to install the new panel, and it's important to apply the glue evenly and avoid air coming under the lid.

Step 1: Applying glue

Apply the B-7000 glue in a thin layer around the perimeter of the smartphone frame, receding 1-2 mm from the edges (so that the glue does not squeeze out). Pay special attention to the corners and areas around the camera - here the cover should fit tightest.

Step 2: Laying the plumes

Carefully connect the fingerprint scanner and camera plumes to the motherboard, make sure they are not twisted or stretched, the scanner plume should lie flat, without clamping.

Step 3: Sticking the lid

Line the new lid over the charging socket and press it gently, starting at the bottom. Then gradually press the edges against the frame, squeezing out the excess glue. Use a soft roller or credit card to evenly distribute the pressure.

Step 4: Final fixation

Place your smartphone under the press (e.g., put a heavy book on top) for 10 to 15 minutes, then check if there are any gaps left, and if the lid is not glued to the edges, warm up the place with a hairdryer and press it again.

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Don't turn on your smartphone immediately after assembly! let the glue dry completely (at least 1 hour), otherwise the cover may shift.

Common Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when replacing the lid, and here are the most common problems and ways to prevent them:

1.The lid is receding at the edges in a day or two.

The reason: not enough glue or poor surface degreasing, so you can use the B-7000 and clean the frame thoroughly with alcohol.

2.The fingerprint scanner is not working.

The reason is, the plume is damaged or it's not connected properly, solution: check the integrity of the plume and the contact density in the connector.

3. Bad network signal or Wi-Fi

The reason: no antenna tracks on the new lid or damage to them. Solution: buy only metallized lids.

4.The lid cracked during installation

The reason: excessive pressure or uneven heating, solution: warm the lid evenly and press it without fanaticism.

5. There are air bubbles under the lid.

The reason is: improper application of glue or rushing to glue, solution: squeeze air from the center to the edges with a soft roller.

Checking the performance after replacement

Once assembled, you need to test all the functions of the smartphone to make sure that nothing is damaged.

• 📶 Cellular and Wi-Fi: Call someone, check the speed of the Internet.
• 📷 Camera: Take a photo on the main and front cameras, check autofocus.
• 👆 Fingerprint Scanner: Add a New Print and Unlock Your Phone.
• 🔊 Speakers and microphone: listen to music, record a voice message.
• 🔋 Charging: Connect the charger and make sure the phone is charging.

If something's not working:

• Check the density of the plumes fitting - they may have moved away during assembly.
• Examine the antenna contacts – they should touch the metallized tracks on the lid.
• If there is a problem with the camera or scanner, reconnect the plumes or check them for damage.

⚠️ Warning: If the lid is overheated after you replace the lid, you may have blocked the vents with glue. Carefully remove the excess and make sure there are microgaps between the lid and the frame to circulate air.

Alternatives: When a replacement is not needed

It is not always necessary to completely replace the lid, and in some cases, you can do with less radical methods:

1.Cracks on the glass

If the lid is cracked but not broken, you can apply a special glass glue (like Loctite 3301) to the cracks and polish the surface, which will not restore the original appearance, but will prevent further cracks from spreading.

2. Unstuck corners

If the lid has only moved in a few places, warm up these areas with a hair dryer and apply a drop of B-7000 glue under the edge, then press it. Use the clamps to fix for 10-15 minutes.

3.Abrasions and scratches

Small scratches can be removed with polishing using GOI paste or special wipes for glass. Deep scuffs hide a vinyl film or a case with a transparent back panel.

4. Problems with antennas

If the signal deteriorates but the cover is intact, check the contacts of the antennas under the lid. Sometimes it is enough to clean them with alcohol and press the lid tighter.

FAQ: Answers to Frequent Questions