POCO F3 Charging Port Replacement Guide | Redmi K40 / Xiaomi Mi 11X/11i

Hi everyone, welcome back to Geardo.
Today, we will show you how to replace the charging port and bottom microphone on the Poco F3, also known as the Xiaomi Mi 11X and Redmi K40.

If your phone is not charging properly, has a loose cable connection, or the microphone is not working during calls or recordings, replacing the charging port board (which includes the bottom microphone) can resolve these issues. This guide is beginner-friendly, so just take it step by step.

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Repair Overview

• Device Type: Smartphone
• Repair Type: Charging Port & Microphone Replacement

Repair Difficulty: ★★★☆☆ (Moderate)

• Estimated Time: 30–45 minutes

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Reasons for Repair

• Phone not charging or charging intermittently
• Loose charging cable connection
• Fast charging not working
• Microphone not working during calls
• Voice recordings sound muffled or unclear
• USB connection not recognized by a computer

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Before You Begin

Compatibility and Model Numbers

• Redmi K40 Series ( Redmi K40 / K40 Pro / K40 Pro Plus) 
• Xiaomi 11x / 11i Series
• Poco F3 Series

Model Numbers : M2012K11AG, M2012K11AC, M2012K11C, M2012K11AI, M2012K11I

This guide is based on the Redmi K40, which shares identical design with the Poco F3 and Xiaomi Mi 11X / Xiaomi Mi 11i. These are rebranded regional models, but always watch for minor internal differences during the repair.

Tools Required

• Mobile phone heating pad or hairdryer/heat gun
• Plastic pry tool / card pry
• Suction cups
• Phillips #00/#000 screwdrivers
• Torx (T2/T3/T4) screwdrivers
• Flathead screwdriver
• Tweezers (for connectors)
• B7000 glue or double-sided adhesive (for back cover)
• Rubber bands or bonding clips to secure the back cover

How to Find Tools and Parts

• Heating pad – https://amzn.to/3H0tHzJ
• Portable Heat Gun – https://amzn.to/4mszih1
• Clamps https://amzn.to/3GYJT4w
• STREBITO 142 Piece Repair Tool Kit https://amzn.to/3UO1jUx
• Glue | Adhesive https://amzn.to/46exVxe
• Compatible Parts –
  • Battery – https://amzn.to/4t0Aw6W
  • Screen – https://amzn.to/48hkKfR
  • Other Parts – https://amzn.to/4cF5E69
• Silicone Work Repair Mat https://amzn.to/45Emz5l

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Protect Your Phone 

• Best Premium Case https://amzn.to/4cF5E69 
• Screen Protector https://amzn.to/423YP86

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Step-by-Step Charging Port & Microphone Replacement

Step 1: Power Off & Remove SIM Tray

Turn off the device completely. Remove the SIM tray using a SIM ejector tool.

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Step 2: Remove the Back Cover

Heat around the edges of the back cover to soften the adhesive.

• Use a heating pad and select the mobile heating option
• Or use a heat gun or hairdryer

Once heated:

• Use a suction cup to lift slightly
• Insert a plastic pry tool or card
• Carefully cut through the adhesive

Remove the back cover gently.

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Step 3: Remove the Board Frame

• Undo 11 screws securing the frame
• Disconnect the flash connector
• Remove the board frame

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Step 4: Disconnect the Battery

• Unplug the battery connector (right-hand side)

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Step 5: Remove the Speaker Assembly

• Undo 7 screws securing the speaker cover
• Lift it carefully (the antenna is still attached)

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Step 6: Remove the Charging Port Board (with Microphone)

• Disconnect the charging port connector
• Disconnect the antenna cable head
• Remove the charging port board (this includes the bottom microphone)

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Step 7: Install the New Charging Port Board

• Place the new charging port board into position
• Reconnect the connector plug
• Reattach the antenna cable

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Step 8: Reassemble the Speaker

• Place the speaker cover back
• Secure it with 7 screws

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Step 9: Reconnect Components

• Reconnect the sensor connector
• Reconnect the battery connector

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Step 10: Reinstall Frame

• Place the board frame
• Secure it with 11 screws

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Step 11: Seal the Back Cover

Before closing:

• Ensure enough adhesive is present
• Use B7000 glue or new adhesive if needed

Press the back cover firmly:

• Use clips or rubber bands
• Leave it for proper bonding

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FAQs

Q1: Does replacing the charging port fix microphone issues?

Yes. The bottom microphone is integrated into the charging port board, so replacing it can fix microphone problems.

Q2: How do I know if the microphone is faulty?

If people can’t hear you during calls or recordings sound muffled, the microphone may be damaged.

Q3: Can I clean the charging port or microphone instead?

Yes, try cleaning first. If the issue continues, replacement is recommended.

Q4: Is this repair beginner-friendly?

Yes, but it requires careful handling of connectors and adhesive.

Q5: Will this fix fast charging problems?

Yes, if the issue is caused by a faulty charging port.

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Troubleshooting

Q1: Phone still not charging after repair

• Check connector alignment
• Ensure antenna cable is connected
• Try a different charger and cable

Q2: Microphone still not working

• Check if the charging board is properly connected
• Test using voice recorder
• Restart the device

Q3: Charging is slow

• Use original fast charger
• Check for software issues

Q4: Back cover not sealing properly

• Apply new adhesive or B7000 glue
• Use clips longer for better bonding

Q5: Speaker not working after reassembly

• Recheck speaker contacts
• Ensure screws are tightened properly

Related Guides

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