Disassembling the Xiaomi Redmi 7A (often referred to as the Mi 7A) is a process that requires precision, precision and understanding of the design. Unlike the flagship models with moisture protection, this budget device is designed so that the user can replace the battery or screen if necessary. However, before starting to dismantle, you need to clearly understand the risks and prepare the workplace.
The biggest challenge with this model is that it has a strong adhesive layer that holds the back cover, and it can damage the plumes if you don't handle them carefully. If you don't properly dismantle it, you can damage the connectors or the display itself, which occupies most of the front panel. If you've never done electronics repair before, you should carefully study each step before you pick up the tool.
The purpose of this article is to describe in detail the process of opening the case to replace components. We will consider the necessary tools, steps to remove the rear panel, disconnect the plumes and remove the motherboard.
Workplace preparation and necessary tools
To successfully complete the Redmi 7A disassembly task, you will need a specialized set of tools. Using improvised tools such as knives or thick needles is strongly discouraged, as they can damage plastic or injure you, the main tool will be a suction cup to lift the lid and a thin mediator or spatula to dissect the adhesive layer.
It is also important to ensure good lighting: small screws and thin plumes are not visible in dim light, which increases the likelihood of error. It is recommended to use a desk lamp with cold light, so that the eyes do not get tired during prolonged work.
Here is a list of what to do on the table before starting:
- 🔧 Set of screwdrivers (mandatory presence of cross-haired) PH000 and PH00)
- 📱 Plastic suction cup for screen/cover
- 🪚 Thin plastic mediator or spatula
- 🔥 A hair dryer or thermophene (to soften glue)
- 🧲 Magnetic mat or organizer for screws
Special attention should be paid to the organization of space. The screws in Xiaomi can vary in length even within the same board. If you screw a long screw into a short hole, you can punch the tracks on the board or damage the case. Use a magnetic mat or just spread the screws in order of their extraction.
⚠️ Warning: Before starting any work, be sure to completely turn off the smartphone. Attempting to turn off the battery or display plume under voltage can lead to a short circuit and the power controller fails.
The work surface should be clean, dry and free of static electricity. It is advisable to use an antistatic mat, but at home a clean desk without synthetic fabrics will do. Make sure you have enough space to accommodate all parts of the case.
☑️ Preparation for disassembly
Removal process of the back cover
The most time-consuming step is to separate the back from the main body, and in the Redmi 7A, it is supported by a two-factor mount: a powerful perimeter adhesive layer and several screws hidden under decorative elements or a logo, always starting with heating.
Use a hair dryer to warm the perimeter of the back cover. Don't keep the hot air flowing at one point for too long to overheat the internal components or the plastic itself, which can deform. The optimal heating temperature is about 80-90 degrees, the cover should get hot to the touch, but not melt.
After warming up (usually 2-3 minutes), place the suction cup at the bottom of the back cover, closer to the center, but avoiding the camera area. Pull the suction cup up, creating tension, while gently inserting the mediator into the resulting gap. Move the tool along the perimeter, cutting the glue.
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If the lid doesn't lend itself, don't put too much effort into it. It's better to reheat the edges with a hairdryer for 30-40 seconds than break plastic latches.
It is important not to enter the tool too deeply, so as not to damage the plume of the fingerprint scanner (if you have one in your modification) or the plume of the main camera, which can pass close to the edges.
When the perimeter is cut, don't rush to slash the lid. Check if there are any screws left in the corners or under the logo. In some Xiaomi revisions, screws can be hidden under stickers. Carefully lift the lid and look inside.
Dismantling internal components and protection against statics
When you remove the back cover, you see the inside of the smartphone, and the motherboard is on top of it, and the metal plate is on the screen, and the battery and the charging connector are on the bottom, and all the connections are protected by screws.
The first thing you do is turn off the power, find the plume that goes from the battery to the motherboard, gently put a plastic blade or nail (not metal!) on it, and disconnect it from the connector, which will turn off the device and protect the boards as you go on.
Next, you have to unscrew all the visible screws that lock the metal plates, and there are several of them in the Mi 7A, which hold the battery protection, the charger protection, and the motherboard protection itself.
Here are the main nodes that require attention at this stage:
- 🔋 Plastic locking battery (usually 2 screws)
- 🔌 Lower charge board (attached by screws to the body)
- 📡 Antenna contacts (golden springs on the ends)
- 📷 Camera module (fixed by screw and plume)
When removing metal plates, be careful with the antenna contacts, these are small spring-loaded elements that are easily lost, and if this contact is lost, you must install it in place when you assemble it, otherwise the network signal will disappear.
⚠️ Warning: Metal plates have sharp edges. Be careful when removing them, so as not to cut your fingers or scratch the display matrix on the inside.
Once all the screws and plates are removed, the motherboard becomes available, but it still holds on to the plumes, and they need to be turned off in a strict sequence, from the largest to the thinnest.
Extraction of motherboard and modules
Now that all the screws are twisted and the plates are removed, you can start to extract the brain of the device. The Xiaomi 7A motherboard sits tightly in its bed, but not glued to it. The main thing is not to pull it sharply.
First, disconnect all the remaining plumes: the display module, the main camera plume, the front camera, the button plume and the bottom speaker. Use a plastic blade to turn off the plumes by putting the connector up from the bottom up.
Pay special attention to the plume of the display. It's wide and fragile. If you damage the tracks on this plume, the screen will stop working or you will see artifacts of the image, and once you turn off all the connections, the board is free.
Carefully raise the toll by the edges, swaying slightly from side to side to get out of the seats. Don't take on chips or capacitors - just textolite or metal frames.
Camera nuances
When removing the board, make sure you don’t get caught on the antenna cable (if you have one in your version) or the vibrator motor, which can be mounted on the board or body.
Replacement of the battery and lower board
A common cause of disassembly is a battery change. In the Redmi 7A, the battery occupies almost the entire bottom half of the body and is glued to double-sided tape. You can't just pull it out, you need heating.
Use a hair dryer again to warm up the back of the case in the battery area (now, when the lid is removed, warm through the metal/plastic of the case). The heating will weaken the glue. Use a suction cup or special strips to pull the batteries out.
Never try to tamper with a screwdriver or knife! a puncture of a lithium polymer battery will cause an instant fire or take off