Xiaomi Redmi 7 with factory code m1903c3gg is one of the most popular budget smartphones of the brand, released in 2019. Despite its simplicity of design, its disassembly requires accuracy: fragile battery plume, glue fixation of the rear cover and the risk of damage to flexible cables make the process unconventional for beginners.
Before you start, consider that self-disassembly deprives the warranty (if it is still valid) and can lead to irreversible damage to the board if the battery is not properly removed. 80% of breakdowns after disassembly are to blame for skewed latches or ragged plumes, which we will disassemble separately.
If you're looking for a battery replacement, a speaker, or a camera, below you'll find step-by-step photos, screw layouts, and tips for bypassing pitfalls. For complex repairs (like soldering connectors), you'd better go to the service -- but basic operations are quite possible even for beginners.
Preparation: security tools and measures
To disassemble the Xiaomi m1903c3gg you will need a specialized set, which can be bought for 300-500 rubles on AliExpress or in electronics stores.
- 🔧 Plastic mediators (2-3 pieces) - to separate the back cover. Metal blades scratch the body!
- ⚙️ Torx screwdriver T3 and T4 — Redmi 7 screws are this big, and the screw screwdrivers won't fit.
- 🔋 Suction (optional) - helps to lift the cover after warming up.
- 🔥 Dryer or thermo-air station - for softening the glue (temperature 60-80)°C).
- 🧲 Magnetic mat - so as not to lose the screws (there are 12 pieces!).
⚠️ Warning: Do not use a knife or scissors to lash the lid, it is almost guaranteed to lead to cracks on the plastic. Also avoid overheating: if you keep the hair dryer longer than 2 minutes in one place, you can melt the internal elements.
Before starting work, it is mandatory to:
- Turn off the phone and remove it. SIM-scatter-card.
- Discharge the battery to 20-30% – this will reduce the risk of fire in case of accidental circuit.
- Make a backup of the data – after disassembly, you may need to reset the settings.
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If you don't have a hair dryer, you can use hot water in a plastic bag: put the phone in a water bag (70°C) for 1-2 minutes - the glue will soften. But don't overdo it: moisture can leak in!
Step 1: Removing the back cover
The Redmi 7's back panel is perimeter-sticked and latched, and the challenge is not to damage the antenna contacts (thin metal strips at the edges) that often come off when the underdog is sloppy.
Algorithm of action:
- Warm up the phone edge with a hair dryer (especially the bottom part where the battery is) for 1-1.5 minutes.
- Insert a plastic mediator into the gap between the lid and the case at the USB-C connector.
- Carefully drive the mediator along the edge, gradually lifting the lid. If you feel resistance, warm up the place again.
⚠️ Warning: Don't try to pull the lid off suddenly, with fingerprint scanner plumes and antenna cables underneath, and if the lid doesn't lend itself, check if all latches are snapped (there are 6 latches: 2 on each side and 2 at the bottom).
What to do if the lid is cracked?
After removing the cover, you will see:
- 🔋 Battery with connected plume.
- 📱 Motherboard closed with metal screen.
- 📷 Main camera module (3 units: 12 MP) + 2 MPs + 2 MPs).
- 🎤 Microphone and speaker at the bottom.
Step 2: Shutting off the battery
Before any manipulation of the board, be sure to turn off the battery - this will prevent short circuit. In m1903c3gg, the battery connector is located at the top and is fixed by a small latch.
How to disconnect:
- Put the latch on a plastic shoulder blade (it is white).
- Carefully pull the plume up. Don't pull the wires, just the black connector!
⚠️ Warning: If the battery is swelling (as seen by the deformation of the lid), do not try to remove it yourself - the risk of fire.
Battery plume turned off |Glue warmed up around the battery perimeter |A plastic card for the underdevice is on hand |Gloves are on (optional)
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To remove the battery:
- Warm it with a hair dryer on the back side (through the lid) for 2-3 minutes.
- Put a plastic card on the battery from any angle, and if it doesn't work, warm it up again.
- Do not use metal objects – a puncture of the battery can cause a fire!
Once removed, check the battery for bloating or corrosion. The normal capacity for the Redmi 7 is 4,000 mAh, but it decreases over time. If the phone turns off at 20 to 30 percent charge, it's time to change the battery.
Step 3: Dismantling the motherboard
The board in the m1903c3gg is mounted on 10 Torx T3 screws and one plume, a display cable that is easily damaged. Before unscrewing the screws, take a picture of their location - they are of different lengths!
Procedure:
- Open all the sleeves (begin with the corners).
- Then, make sure you are on the right side of the sleeve.
- Disconnect the connectors: display plume (top), camera plume (left), power button plume (right).
| Vint | Size | Number of | Location |
|---|---|---|---|
| Torx T3 (short) | 3 mm | 4 | By the toll corners |
| Torx T3 (long) | 5 mm | 6 | Downtown and near the connectors. |
| Torx T4 | 4 mm | 2 | Camera attachment |
⚠️ Warning: Don't charge for the connectors, they're soldered to it and can come off. If the charge doesn't go, check if all the screws are unscrewed (especially under the screen!).
After the charge is retrieved, you will have access to:
- 📶 Antenna modules (2 pcs) - attached to the inner side of the cover.
- 🔊 The microphone and the speaker are located at the bottom.
- 📶 Fingerprint scanner - glued to the back cover.
Step 4: Disassembly of the display module
Redmi 7 is glued to a frame and connected to the board with two plumes: display and touch. Replacing it is one of the most difficult operations, because it requires careful warming up and the use of special glue to fix the new screen.
If the goal is to replace the display, do this:
- Warm up the screen edge with a hair dryer (temperature 70–80°C) for 3-4 minutes.
- Insert the plastic mediator into the gap between the screen and the frame (start with the lower right corner).
- Carefully drive the mediator along the edge, separating the glue. Don't press too hard - the glass may crack!
⚠️ Warning: If the screen cracks, stick tape on it before warming up, this will prevent the fragments from crumbled. Also be careful with the flexible plume, which breaks easily when sudden movements.
After screen separation:
- Disconnect both the plumes from the board (they are fixed with latches).
- Check the integrity of the contacts on the plumes - oxidation or contamination can be the cause of the "glitch" touchscreen.
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If you have vertical stripes or a touchscreen that's not working after you change the screen, it's likely that the plume is damaged, and 90 percent of the time, it's the plume that's going to help you replace it, not the display itself.
Common Mistakes and How to Avoid Them
Even experienced craftsmen sometimes make mistakes when disassembling the Xiaomi m1903c3gg.
- 🔧 Torn screws, use a high-quality Torx screwdriver and don't use excessive force. If the screw doesn't go, drop it. WD-40.
- 🔥 Overheating board - the hair dryer should be at a distance of 5-10 cm from the body. Temperature above 90°C can melt plastic parts.
- 📱 Damaged display plume – always disconnect it last and raise the charge from the opposite side.
- 🔋 Short circuit – before any manipulation of the board, turn off the battery and discharge static electricity (touch the grounded object with your hand).
If the phone does not turn on after assembly:
- Check if the battery is connected.
- Make sure all the plumes are tightly inserted into the connectors.
- Try charging the device – sometimes after disassembly it takes 5-10 minutes to charge the phone to “live”.
If the problem persists, the fee may have been damaged or the contact may have fallen off, and only a diagnostic at the service center will help.
Assembly: reverse sequence and testing
To assemble Redmi 7 need in reverse order, but taking into account a few nuances:
- 🔧 Screw the screws cross-curl to avoid skewing the board.
- 📱 Before fixing the screen, check the touchscreen - connect the plumes and temporarily turn on the phone.
- 🔋 The battery should lie flat, without skewing. If it walks, put a thin double-sided tape.
After assembly:
- Turn on the phone and check: Touchscreen (swipe your finger all over the screen), speaker and microphone, cameras (take a test shot), charging (plug the cable).
If everything works, seal the lid with tape around the perimeter for additional fixation (for 1-2 days).
⚠️ Warning: If the phone overheats or discharges quickly after assembly, it's likely that the battery is not tightly connected or the power plume is damaged.
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To check the leakage after assembly, put the phone down on a flat surface and press the lid slightly, and if you hear a creak or feel a backlash, there are gaps somewhere.