Replacement of the back cover on Xiaomi Redmi Note 9: a complete analysis with photos and tips

The back cover of the Xiaomi Redmi Note 9 is one of the most vulnerable parts of the smartphone, and over time it gets scratched, cracked from falls or just bored with the appearance. Many users decide to replace them, but are afraid to damage the internal components. In fact, the procedure is not as difficult as it seems — enough tools, patience and knowledge of the key nuances.

In this article, we'll take you through the whole process from A to Z, from choosing a new lid to final assembly. You'll learn what tools are really needed (and what you can do without), how not to damage the plumes and battery, and what to do if the glue doesn't hold. Separately, we'll focus on common mistakes that can stop a smartphone from turning on or losing water protection. For clarity, we'll give a comparative table of original and unoriginal covers, and give advice on the choice of glue.

When to change the back cover: 5 obvious reasons

It's not always a good idea to replace the lid -- sometimes it's just a case or a polish, but there are situations where you can't do it without repair.

• 🔧 Cracks or chips – even small damages disperse over time, revealing the internal details.
• 💧 Detachment of glue - if the lid began to "play" and emit creaks when pressed.
• 🔋 Battery bloating – in this case, the lid is often lifted and has to be changed along with the battery.
• 🎨 The Redmi Note 9 came in several colors, and the original covers can be found on the secondary market.
• 🛠️ Repair after falling – if the impact occurred on the back, antenna lines or mounts could have been affected.

It’s important to understand that replacing the lid resets the factory’s IP53 water protection — even if you’re using original parts and quality glue. If the smartphone is often caught in the rain or used in wet conditions, you should avoid direct contact with water after repair.

⚠️ Warning: If the lid is blown by a dead battery, replace the battery first! Installing a new lid on a bloated battery will result in re-detachment or cracks.

Which lid to choose: original vs. replica

There are three types of back covers available on the market for the Redmi Note 9:

1. Original (OEM) - removed from new or used smartphones, perfect for mounts and holes, but more expensive.
2. Quality replicas -- produced by third-party companies, but with respect to size, and may vary in texture or color.
3. Cheap fakes – often have inaccurate camera cutouts or sensors, poorly planting glue.

Where to buy it?

• 🛒 Xiaomi’s official service centers are original details, but high price.
• 🌍 AliExpress, eBay – a large selection of replicas, but a long wait for delivery.
• 🏬 Local parts stores – you can touch before buying, but a limited range.

Tools required: What not to miss

Replacement of the lid requires a minimal set of tools, some of which are manageable, but this will increase the risk of damage:

Suction (diameter 5-7 cm) | Plastic mediator or spatula | Thin screwdriver (cross, 1-1.5 mm) |Twincet (for plumes) |Fen or thermoair station (power 300-500 W) | Double-sided tape or glue B-7000 | Alcohol and wipes for cleaning-->

Why these tools?

• 🧲 Suction is needed for inicial removal of the lid - without it it is difficult to overcome factory glue.
• 🔥 The dryer softens the glue, but it is important not to overheat the smartphone (maximum 60-70).°C).
• 🛠️ The mediator should be plastic so as not to leave scratches on the frame.
• 🧴 Clay. B-7000 or 3M VHB — Best fixation options. Avoid superglue!

⚠️ Note: If you have a Redmi Note 9 Pro or Note 9S, instruction doesn't fit - they have a different lid design and clip location! this article is only for the base model of the Redmi Note 9 (merlin).

Step-by-step: how to remove the old cover

Before starting work, turn off the smartphone and remove SIM-The map is off the tray. Follow the algorithm:

1. Heat the lid: Dryer warm the edges of the lid around the perimeter for 2-3 minutes. Keep at a distance of 5-7 cm to avoid melting the plastic. Pay special attention to the corners - there the glue usually holds stronger.
2. Suction compartment: Stick the suction cup closer to the bottom edge (where the charging connector is) and pull up. There should be a gap of 1-2 mm. If the lid does not lend itself, warm up again.
3. Separation by mediator: Put a plastic mediator in the gap and gently lead along the edge, separating the glue. Don't push hard - there are plumes inside! The corners are held tighter, so it's easier to separate them after warming up.
4. Turn off the fingerprint scanner plume: Once the lid is separated, you'll see the fingerprint sensor plume. Carefully unplug it with tweezers (it's attached to the motherboard). Photo of the fingerprint sensor plume The plume is located at the top of the lid, next to the camera. It's black and has gold contacts. Don't pull the wires, just grab the connector!

If the lid doesn't work in some place, don't force it. You better warm up the problem area again. The hardest areas are near the volume buttons and the camera.

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If the glue is too hard, drop a little alcohol into the gap - it will soften the adhesive without heating.

Installation of a new cover: glue, alignment and fixation

Before installing a new lid, carefully clean the smartphone frame of the old glue. Use alcohol and cotton swabs - they do not leave a pile.

• 🔍 Pazam clips - they have to be clean, otherwise the lid will dangle.
• 📶 Antenna lines – they can not be scratched or bent.
• 🔋 Battery fastening – if there is glue left, the new cover can put pressure on the battery.

Then proceed with the steps:

1. Applying glue: If the new cover does not have factory glue, apply a thin layer of B-7000 or 3M VHB around the perimeter, receding 1-2 mm from the edge (so that the glue does not squeeze out).
2. Connect sensor plume: Carefully connect the fingerprint scanner connector to the motherboard. Make sure the contacts match - a skewed connector can damage the plume.
3. Install the lid: Line the lid on the charging connector and press gently, starting at the bottom. Then walk around the perimeter, fixing the clips. For reliability, put the smartphone under the load (for example, a book) for 10-15 minutes.

Check that all buttons (Power, Volume) are pressed without backlash, so if the lid is walking, then there is not enough glue or clips are not clicked.

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After replacing the cover, be sure to check the fingerprint sensor – if it does not respond, the plume is connected incorrectly or damaged.

Frequent Mistakes and How to Avoid Them

Even experienced craftsmen sometimes make mistakes when replacing the lid, and here are the most common problems and solutions.

Another common mistake is to use the wrong glue, such as superglue or moment crystallize over time and can damage the plastic.

• ❌ Excessive heating – plastic can deform.
• ❌ Strong pressure - you can break clips or plumes.
• ❌ Using metal tools – they scratch the frame and cover.

If after replacing the cover, the smartphone began to warm or quickly discharge, most likely, you damaged the thermal paste on the processor or battery plume.

Video Instructions and Additional Resources

For clarity, we recommend watching the video guide for replacing the cover with the Redmi Note 9:

Video: Replacement of the back cover of Xiaomi Redmi Note 9 (Step-by-step) (in English, but with a visual demonstration).

Useful resources:

• 📄 Disassembly scheme - detailed PDF-instruction.
• 🛒 Where to buy tools - an overview of the best sets for repairing smartphones.
• 💬 Xiaomi Forum – discussion of the nuances of replacement (there is user experience with photos).

If you've never taken a smartphone apart, practice on an old device or watch a few videos before work, and this will help you avoid annoying mistakes.

FAQ: Answers to Frequent Questions