Troubleshoot Bluetooth

You are helping the user diagnose and fix Bluetooth connectivity issues.

Task

1. Check Bluetooth service status:

   # Service status
   systemctl status bluetooth
   
   # Is it running?
   systemctl is-active bluetooth
   
   # Is it enabled to start on boot?
   systemctl is-enabled bluetooth
   

2. Check Bluetooth hardware:

   # List Bluetooth adapters
   hciconfig -a
   
   # Or using rfkill
   rfkill list bluetooth
   
   # Check if Bluetooth is soft/hard blocked
   rfkill list
   
   # Detailed hardware info
   lsusb | grep -i bluetooth
   lspci | grep -i bluetooth
   

3. Check Bluetooth controller status:

   # Controller info
   bluetoothctl show
   
   # List controllers
   bluetoothctl list
   
   # Check if powered on
   bluetoothctl show | grep "Powered:"
   

4. Check for firmware issues:

   # Look for firmware errors in journal
   journalctl -u bluetooth | grep -i firmware
   
   # Check dmesg for Bluetooth firmware loading
   dmesg | grep -i "bluetooth\|firmware" | tail -20
   
   # Check kernel modules
   lsmod | grep bluetooth
   

5. Common fixes - Restart Bluetooth:

   # Restart Bluetooth service
   sudo systemctl restart bluetooth
   
   # Reset Bluetooth controller
   sudo hciconfig hci0 down
   sudo hciconfig hci0 up
   
   # Or use bluetoothctl
   bluetoothctl power off
   sleep 2
   bluetoothctl power on
   

6. Unblock Bluetooth if blocked:

   # Check if blocked
   rfkill list bluetooth
   
   # Unblock if soft-blocked
   sudo rfkill unblock bluetooth
   
   # Power on controller
   bluetoothctl power on
   

7. Scan for devices:

   # Start scanning
   bluetoothctl scan on
   
   # Wait 10 seconds
   sleep 10
   
   # List discovered devices
   bluetoothctl devices
   
   # Stop scanning
   bluetoothctl scan off
   

8. Check paired devices:

   # List paired devices
   bluetoothctl paired-devices
   
   # Show info about specific device
   bluetoothctl info DEVICE_MAC_ADDRESS
   

9. Remove and re-pair problematic device:

   # Ask user for device MAC address
   # Remove device
   bluetoothctl remove DEVICE_MAC_ADDRESS
   
   # Scan again
   bluetoothctl scan on
   sleep 10
   
   # Pair device
   bluetoothctl pair DEVICE_MAC_ADDRESS
   
   # Trust device
   bluetoothctl trust DEVICE_MAC_ADDRESS
   
   # Connect to device
   bluetoothctl connect DEVICE_MAC_ADDRESS
   

10. Check Bluetooth configuration:

    # Main config file
    cat /etc/bluetooth/main.conf
    
    # Check for problematic settings
    grep -E "^(Name|Class|DiscoverableTimeout|AutoEnable)" /etc/bluetooth/main.conf
    

11. Check for interference:

    # Check WiFi and Bluetooth coexistence
    iw dev | grep -i channel
    
    # Bluetooth operates on 2.4GHz
    # WiFi on 2.4GHz can interfere
    echo "Consider switching WiFi to 5GHz if available"
    

12. Detailed diagnostics:

    # Bluetooth subsystem logs
    journalctl -u bluetooth --since "1 hour ago" --no-pager
    
    # Kernel Bluetooth messages
    dmesg | grep -i bluetooth | tail -30
    
    # Check for errors
    journalctl -u bluetooth | grep -iE "error|fail|timeout"
    

13. Audio-specific Bluetooth issues:

    # Check PulseAudio/PipeWire Bluetooth modules
    pactl list | grep -i bluetooth
    
    # PipeWire Bluetooth
    pw-cli ls Device | grep -i bluetooth
    
    # Load Bluetooth module (PulseAudio)
    # pactl load-module module-bluetooth-discover
    
    # Restart audio with Bluetooth
    systemctl --user restart pipewire pipewire-pulse wireplumber
    

14. Generate diagnostic report:

    cat > /tmp/bluetooth-diagnostic.txt << EOF
    Bluetooth Diagnostic Report
    ===========================
    Date: $(date)
    
    === Service Status ===
    $(systemctl status bluetooth --no-pager)
    
    === Hardware Detection ===
    $(rfkill list bluetooth)
    $(hciconfig -a)
    
    === Controller Info ===
    $(bluetoothctl show)
    
    === Paired Devices ===
    $(bluetoothctl paired-devices)
    
    === Recent Bluetooth Logs ===
    $(journalctl -u bluetooth --since "1 hour ago" --no-pager | tail -50)
    
    === Kernel Messages ===
    $(dmesg | grep -i bluetooth | tail -30)
    
    === Loaded Modules ===
    $(lsmod | grep bluetooth)
    
    === Configuration ===
    $(grep -v "^#\|^$" /etc/bluetooth/main.conf)
    EOF
    
    cat /tmp/bluetooth-diagnostic.txt
    

Common Issues & Solutions

Bluetooth not starting:

# Check if service masked
systemctl unmask bluetooth
sudo systemctl enable --now bluetooth

Device pairs but won't connect:

# Remove and re-pair
bluetoothctl remove DEVICE_MAC
bluetoothctl scan on
# Wait for device to appear
bluetoothctl pair DEVICE_MAC
bluetoothctl trust DEVICE_MAC
bluetoothctl connect DEVICE_MAC

Audio stuttering or quality issues:

# Check Bluetooth audio codec
pactl list | grep -i "bluetooth\|codec"

# Try different codec
# Edit /etc/bluetooth/main.conf
# [General]
# Enable=Source,Sink,Media,Socket

Bluetooth adapter not found:

# Reload Bluetooth module
sudo rmmod btusb
sudo modprobe btusb

# Or all Bluetooth modules
sudo rmmod bnep btusb bluetooth
sudo modprobe bluetooth
sudo modprobe btusb
sudo modprobe bnep

Random disconnections:

# Increase page timeout
sudo hciconfig hci0 pageto 8192

# Disable power management for USB Bluetooth
# Add to /etc/udev/rules.d/50-bluetooth.rules:
# ACTION=="add", SUBSYSTEM=="usb", ATTR{idVendor}=="YOUR_VENDOR", ATTR{power/autosuspend}="-1"

LE (Low Energy) devices not working:

# Enable LE in bluetoothctl
bluetoothctl
[bluetooth]# menu scan
[bluetooth]# transport le
[bluetooth]# scan on

Reset Bluetooth Completely

If nothing else works:

# Stop Bluetooth
sudo systemctl stop bluetooth

# Remove paired devices cache
sudo rm -rf /var/lib/bluetooth/*

# Restart Bluetooth
sudo systemctl start bluetooth

# Re-pair all devices

Notes

• Most Bluetooth adapters work with btusb kernel module
• Firmware files typically in /lib/firmware/
• Check if kernel has Bluetooth support: zgrep BLUETOOTH /proc/config.gz
• Some devices require specific pairing codes
• Audio devices may need PulseAudio/PipeWire Bluetooth modules
• USB Bluetooth adapters: check with usb-devices | grep -A 10 Bluetooth
• Bluetooth 5.x adapters are backward compatible with older devices
• Distance and obstacles affect connection quality