Webcam not working Ubuntu 18.04

Question

I have installed Ubuntu 18.04, but the applications (Skype, Cheese) says no device found.

I have reviewed several topics on the subject, but none seem to work. Thank you!

Edit: In a beginning the output of ls -l /dev/video0 is:

ls: Cannot access an '/dev/video0': file or directory does not exist.

Then when I put

sudo mknod /dev/video0 c 81 0 

We have the output for ls -l /dev/video0 is:

crw-r--r-- 1 root root 81, 1 Apr 19 22:25 /dev/video0

Output getfacl /dev/video and ls -ltrh /dev/video*

Output lsusb and v4l2-ctl --list-devices

Output 'Cheese' by terminal. And when the camera is activated, it says: 'No device found'

Solution

The group and permissions for your /dev/video0 are not correct. The groop root for your /dev/video0 will deny access to the camera for users outside this group.

The output of ls -l /dev/video0 should look like this:

crw-rw----+ 1 root video 81, 1 Apr 19 22:25 /dev/video0

Try fixing the group by running:

sudo chown root:video /dev/video0

Then fix permissions by running:

sudo chmod 660 /dev/video0

Comments

[Jonatã]

What is the output of lsusb and v4l2-ctl --list-devices?

[Raffa]

The groop root for your /dev/video0 will deny access to the camera for users outside this group. Try running sudo chown root:video /dev/video0 then run sudo chmod 660 /dev/video0. Also please avoid adding screenshots when you can copy and paste the output in the question.

[Raffa]

@J.PabloCN no spaces .... like this /dev/video0 NOT like this / dev / video0

[Raffa]

@J.PabloCN also no spaces in this root:video NOT like this root: video

[Raffa]

@J.PabloCN Spaces are: sudo then space chown then space root:video then space /dev/video0 then press Enter

[J.PabloCN]

OK! thank you very much. Now the light on the camera built into the notebook turns on. But still the Cheese app, can't find any device.

[Raffa]

@J.PabloCN Did you run sudo chmod 660 /dev/video0 as well?

[J.PabloCN]

I edit the question. I forgot to mention that initially the directory 'dev/video0' doesn't exist, but when I put 'sudo mknod /dev/video c 81 0' it started to work.

[Raffa]

@J.PabloCN /dev/video0 is not a directory it is a node ie. a file descriptor and can be referred to as a file. So you fixed your cam?

[J.PabloCN]

nop. I have windows10/Ubuntu installed, and the windows camera also has an error and does not work. Maybe the problem is some bad installation

[Raffa]

@J.PabloCN Windows has its own settings that are not affected by what you do in Ubuntu. This sounds like a hardware issue or BIOS settings issue if it affects both operating systems.