Logitech Speakerphone with Linux Mint

 My Logitech USB Speakarphone has stopped working since I did something wrong (which I don't remember).  Various troubleshooting and zillions of searches on the Internet did not fix the issue, until today.

The issue was the device did not make any sound at all.  Checking via ALSA and Kernel log said everything was fine as shown below:

$  lsusb

...

Bus 002 Device 011: ID 046d:0a06 Logitech, Inc. 

Bus 002 Device 009: ID 046d:c51c Logitech, Inc. 

...

$ inxi -A

Audio:     Device-1: Intel 82801I HD Audio driver: snd_hda_intel 

           Device-2: ViXS Systems XCode 2100 Series driver: N/A 

           Device-3: AMD Cape Verde/Pitcairn HDMI Audio [Radeon HD 7700/7800 Series] driver: snd_hda_intel 

           Device-4: Logitech type: USB driver: snd-usb-audio 

           Sound Server: ALSA v: k4.15.0-135-generic 

$ dmesg | ack -i Logitech

[    4.347659] usb 2-7.3.1: Manufacturer: Logitech

[    4.351947] input: Logitech VoIP USB Dual RF Receiver as /devices/pci0000:00/0000:00:1d.7/usb2/2-7/2-7.3/2-7.3.1/2-7.3.1:1.0/0003:046D:C51C.0002/input/input5

[    4.408172] hid-generic 0003:046D:C51C.0002: input,hidraw1: USB HID v1.11 Keyboard [Logitech VoIP USB Dual RF Receiver] on usb-0000:00:1d.7-7.3.1/input0

[    4.412142] input: Logitech VoIP USB Dual RF Receiver as /devices/pci0000:00/0000:00:1d.7/usb2/2-7/2-7.3/2-7.3.1/2-7.3.1:1.1/0003:046D:C51C.0003/input/input6

[    4.472241] hid-generic 0003:046D:C51C.0003: input,hiddev1,hidraw2: USB HID v1.11 Mouse [Logitech VoIP USB Dual RF Receiver] on usb-0000:00:1d.7-7.3.1/input1

[    4.744033] usb 2-7.3.2: Product: Logitech EasyCall Speakerphone

[    4.744035] usb 2-7.3.2: Manufacturer: Logitech

[    4.936663] usb 2-7.7.2: Manufacturer: Logitech

[    4.944780] input: Logitech USB Laser Mouse as /devices/pci0000:00/0000:00:1d.7/usb2/2-7/2-7.7/2-7.7.2/2-7.7.2:1.0/0003:046D:C069.0006/input/input9

[    4.944928] hid-generic 0003:046D:C069.0006: input,hidraw5: USB HID v1.10 Mouse [Logitech USB Laser Mouse] on usb-0000:00:1d.7-7.7.2/input0

$ aplay -l

**** List of PLAYBACK Hardware Devices ****

card 0: Loopback [Loopback], device 0: Loopback PCM [Loopback PCM]

  Subdevices: 8/8

  Subdevice #0: subdevice #0

  Subdevice #1: subdevice #1

  Subdevice #2: subdevice #2

  Subdevice #3: subdevice #3

  Subdevice #4: subdevice #4

  Subdevice #5: subdevice #5

  Subdevice #6: subdevice #6

  Subdevice #7: subdevice #7

...

...

card 3: Speakerphone [Logitech EasyCall Speakerphone], device 0: USB Audio [USB Audio]

  Subdevices: 0/1

  Subdevice #0: subdevice #0

$ cat /proc/asound/modules 

 0 snd_aloop

 1 snd_hda_intel

 2 snd_hda_intel

 3 snd_usb_audio

$ cat /proc/asound/cards 

 0 [Loopback       ]: Loopback - Loopback

                      Loopback 1

 1 [Intel          ]: HDA-Intel - HDA Intel

                      HDA Intel at 0xfe7f4000 irq 32

 2 [HDMI           ]: HDA-Intel - HDA ATI HDMI

                      HDA ATI HDMI at 0xfebfc000 irq 33

 3 [Speakerphone   ]: USB-Audio - Logitech EasyCall Speakerphone

                      Logitech Logitech EasyCall Speakerphone at usb-0000:00:1d.7-7.3.2, full speed

Tried to see from Pulse Audio control, it did not show the USB speakerphone device at all.

Turned out it was due to the presence of /etc/asound.conf.  After I renamed it to something else, my audio started to work!