Xiaomi Mi 8 step-by-step assembly: from mounts to final check

Building the Xiaomi Mi 8 after disassembly is a task that requires precision and understanding of the device’s design. This model, released in 2018, is still popular today thanks to its powerful hardware (Snapdragon 845 processor, 6 GB of RAM) and premium design with a glass rear panel. However, improper assembly can lead to loss of the tightness of the case, damage to the plumes, or even short circuit due to a loosely secured battery.

In this article, we will look at the A-Z build process, from the workplace to the final diagnosis, and focus on the Mi 8’s weak points, the fragile charging connector, the thin camera plumes and the power button that often fails when installed improperly, and if you’ve taken a phone apart to replace a battery, display or speaker, these instructions will help avoid typical errors.

Before you start, make sure all the parts are in place. Xiaomi Mi 8 has 17 screws of different sizes (from 1.2 mm to 1.8 mm), 5 flexible plumes and 3 adhesive pads. Losing even one screw can lead to a backlash of the board or a thin fit of the screen. If you are not sure of your abilities, you should contact the service center.

1. Preparation of the workplace and tools

The Xiaomi Mi 8 requires clean, well-lit space, and an antistatic mat table is perfect to protect the motherboard from static electricity.

• ✅ Set of screwdrivers (cross-cross-haul) PH00 and PH0, flat-footed 1.0 mm)
• ✅ Plastic blades (for smacking of plumes and latches)
• ✅ Tweezers (for installing small parts, such as sim lot)
• ✅ Thermoclee or double-sided scotch (for battery fixation)
• ✅ Loop or magnifying glass (to check contacts)

Important: all Mi 8 screws are different lengths. To avoid confusing them when you build them, spread them out in containers or stick a diagram on paper indicating the mounting places. For example, screws under 1.2 mm are used to mount the camera and speaker, and 1.8 mm for fixing the motherboard.

⚠️ Warning: If you've been replacing the battery, don't turn the phone on immediately after assembly! let the heat glue dry for at least 2 hours, otherwise the battery may shift and damage the plumes.

Installation of motherboard and plumes

Start by placing the motherboard at the bottom of the case, make sure all connectors are clean — dust or oxide deposits can cause contact problems.

• 🔌 The power supply (should be tightly "clicked»)
• 📶 Antenna contacts (check if the "mustache" is bent»)
• 🔊 Dynamic plume (fragile, do not overflex!)

Connect the plumes in the following order:

1. Display plume (the widest, fixed by a latch)
2. Touch panel plume (thin, with gold contacts)
3. The tail of the front camera and sensors (shortest)

Once connected, gently press each plume with a plastic blade - they should "sit" to the end. If the contact is not dense, the screen may flash or not respond to touch.

The display plume is plugged in to the point.|Sensor plume not twisted|Antenna contacts are not bent|The screws of the board are crisscrossed-->

Installation of the battery and cooling system

The battery in Xiaomi Mi 8 is glued to the body, and replacing it is one of the most difficult operations.When building, use a new thermal glue (for example, B-7000) or double-sided 3M 9448A tape. Apply the glue with a thin layer, avoiding contact!

After installing the battery, check:

• 🔋 Insulation film between battery and board (prevents circuiting)
• 🔥 No swelling or damage to the battery
• 📏 The gap between the battery and the housing (should be 1-1.5 mm for ventilation)

The Mi 8 cooling system includes a graphite film and a copper tube.

1. The graphite film fits tightly to the processor.
2. The tube is not clamped by screws (this worsens the heat sink).

⚠️ Warning: If the phone overheats after assembly, check if the glue hits the radiator. Remove the excess alcohol and repeat the assembly.

Build the case: buttons, speakers and cameras

Now, to the little things that make us more comfortable, start with the buttons.

• 🔘 The power button must click clearly, without backlash. If it fails, check the spring mechanism.
• 🔊 Volume buttons - often lost when disassembling. Make sure the metal ears are in the slots.

The Mi 8 speakers are attached to glue and screws.

1. Check the integrity of the rubber gaskets (they seal the speaker).
2. Make sure the speaker grid is not bent (otherwise the sound will be muffled).

Cameras are the most vulnerable, and the main camera (12 MP, f/1.8) is fixed by four screws.

Focus (photo text at 30 cm distance, it should be clear) Stabilization (start recording the video and shake the phone - the image should not "jump").

Installation of the display and sealing of the housing

Xiaomi Mi 8 Display is a Display AMOLED-It's a matrix with an integrated sensor:

1. Make sure there is no dust on the tape around the perimeter of the screen.
2. Connect the plumes to the full fixation of the display (otherwise you will not be able to correct).
3. Press the screen evenly, starting from the center to the edges to avoid bubbles.

For sealing, use:

• 🔧 Clay. LOCTITE 406 (for fixing glass)
• 🧴 Insulation tape (to protect plumes from corrosion)

After assembly, check:

Sensor sensitivity (test Settings → Display → Screen calibration) Color rendering (whether yellow or broken pixels).

💡

If after assembly the screen "goes away" at the edges, warm it up with a hair dryer at minimum power (60 ° C) and press the load for 10 minutes.

Final inspection and diagnosis

Before first inclusion:

1. Check all screws – they should be curled cross-to-cross to avoid board skewing.
2. Make sure there are no foreign objects under the charge (cogs, pieces of plastic).
3. Connect the charger and check the indication (the red/orange LED should be on).

After activation, perform the tests:

• 📞 Call - Check the microphone and speaker.
• 📷 Camera - take a video in 4K and check for stabilization.
• 🔋 Battery – Run AccuBattery to check capacity.
• 🌡️ Temperature - play at PUBG Mobile 15 minutes (processor should not be heated above 75 minutes)°C).

If a malfunction is detected:

Screen not turning on → check the display plume and battery contacts. Phone overheating → remove the cover and check the thermal paste. Camera not working → reconnect the plume or update the firmware.

💡

If after the assembly there were "glitch" (spontaneous reboots, artifacts on the screen), most likely, the problem is in poor contact of plumes or screws, twisted not to the end.

7. Frequent mistakes and how to avoid them

Even experienced craftsmen make mistakes when building Xiaomi Mi 8.

• 🛠️ Twisted screws → Use a dynamometer screwdriver with a force of no more than 0.3 N·mm.
• 🔌 Contorted antenna contacts → It degrades the signal. Straighten them with a needle, without taking them off the board.
• 📱 Dust under the screen → remove with a sticky roller to clean the lenses.
• 🔋 The wrong polarity of the battery → The phone won't turn on. +/– battery-powered.

If the phone does not turn on after assembly:

1. Connect to charging for 10 minutes (possibly drained battery).
2. Try running in Fastboot mode (clip Volume Down + Power).
3. Check the voltage at the battery contacts with a multimeter (should be 3.7-4.2 V).

FAQ: Answers to Frequent Questions