Raspberry pi 3B hardware running ubuntu mate armhf (32 bit), not working with audio?

I have a raspberry pi 3 B hardware running ubuntu mate 18.04 (amfhf, 32bit). then the pi 3B device didn't work with audio through built-in 3.5 speaker output. Even though using rasp-config, I setted the audio path to built-in 3.5 speaker output, I could not hear any audio with 3.5 speaker-output when playing the video using VLC player or GNOME MPV player. the video did work with the pi device but audio did not work with speaker output. When I setted the audio voice to auto mode using rasp-config, the same problem happened. However, I did not tested the pi with hdmi audio path because I have only hdmi monitor with not voice but video function.

Any help? Is there anybody with the same problem with audio stream?
Then,

I don't understand about 'built-in microphone', since Pi3B doesn't have one. I have a video connection via HDMI which doesn't have audio so have a break-out for the audio from the HDMI connector, and have audio when using VLC to play videos.
Derek

I'm sorry about the microphone. I'm about to ask about not microphone but built-in speaker output and hdmi audio output.
I just edited my original question's post.
Sorry,

Only 2 thoughts at the moment:

  1. have you got "hdmi_ignore_edid_audio=1" in config.txt?
  2. have you got the correct lead for the 3.5 socket - there are several different types, but only a 4-pole with the correct connections for left and right will work.
    Derek