Fix Bluetooth Keyboard Connection Issues | Generated by AI

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Based on the bluetoothctl output showing [DEL] Device when attempting to connect, here’s a precise solution:

Immediate Fix for Connection Deletion Issue

1. Remove existing device records (critical for stale configurations):

   bluetoothctl
   remove F4:73:35:78:28:4E  # Remove keyboard
   remove 24:27:30:24:C8:31   # Remove potential interfering device
   exit
   

2. Reset Bluetooth stack:

   sudo systemctl stop bluetooth
   sudo rm -rf /var/lib/bluetooth/*
   sudo systemctl start bluetooth
   

3. Repair using correct sequence:

   bluetoothctl
   power on
   discoverable on
   pairable on
   agent on  # Enable passkey agent
   scan on
   

   • Put K380 in pairing mode (LED blinking rapidly)
   • When keyboard appears:

     pair F4:73:35:78:28:4E
     

   • Immediately type the 6-digit passcode shown on-screen (e.g., 123456) on the keyboard and press Enter
4. Connect only after successful pairing:

   connect F4:73:35:78:28:4E
   trust F4:73:35:78:28:4E
   scan off
   quit
   

Why This Happens

• The [DEL] Device occurs because:
  • Bluetooth stack detects connection failure and purges the device record
  • Missing pairing step before connection attempt
  • Possible RF interference from other devices (like the midea device)

Additional Critical Checks

1. Verify antenna connection:
   • Ensure Bluetooth antennas are screwed into your MSI motherboard’s rear I/O panel
2. Check kernel drivers:

   dmesg | grep -i bluetooth
   

   Look for errors like hci0: command timeout or Firmware failed to start

3. Update firmware (if timeout errors appear):

   sudo apt install linux-firmware
   

4. Test with minimal environment:

   sudo rfkill unblock all
   sudo systemctl stop NetworkManager  # Temporary stop
   sudo systemctl restart bluetooth
   

If Still Failing

1. Alternative pairing method (bypass agent):

   echo -e 'remove F4:73:35:78:28:4E\npair F4:73:35:78:28:4E\nconnect F4:73:35:78:28:4E\ntrust F4:73:35:78:28:4E' | bluetoothctl
   

2. Check keyboard battery (critical for Bluetooth):
   • Replace battery if voltage is low (K380 uses CR2032 x 2)
3. USB Bluetooth adapter test:
   • If internal Bluetooth is problematic, try a $10 CSR4.0 USB adapter

Expected success indicators:

• Pairing successful message
• Connection successful in bluetoothctl
• dmesg showing HIDP: Bluetooth HID device driver

After pairing, your K380 should survive reboots. If disconnections recur, check journalctl -u bluetooth -f for real-time errors.

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