Premiere Pro: can't switch on A1 button

[ernas89528242]

Hello from Switzerland, I am editing a wedding video. I used a mix of footage (mirrorless and DSRL). When I started editing all my clips had visible audio. Now when I drop certain clips on the timeline some don't have audio, others do. What I noticed is that the first A1 button is not blue (the one completely to the left), whereas the V1 is activated.  But for some reason I can't click on it. 

What I also noticed that I can only drag the video (the audio button is even not visible), but the clips do have audio.

I am lost, has anyone experienced this before?

Thanks for your reaction and have a great day, Erna

[Ann Bens]

Open clip in source monitor first.

[ernas89528242]

Hello everyone, I solved it. It had apparentely to do something with the sequence settings....!

[Zadianovita]

Hello, can you explain more about the sequence settings, because i am having the same problem as you. Thanks

[Peru Bob]

https://community.adobe.com/t5/premiere-pro-discussions/faq-why-does-audio-or-video-not-go-to-the-tr...