Question:
Can I watch short videos about something that is mechazek emuna ? Even if there is a bit of music ? Or even if there is no music at all.
Answer:
Hamakom yinachem eschem b'toch shar aveilei Zion v'Yerushalayim.
Watching the videos are part of your learning, and even if there is some background music, which is only secondary to the shiur you are listening to. Therefore is it not a problem.
Best wishes
Sources:
שו"ת מקדש ישראל ס' כ"ב ב'.