strnglyfmlr

I just dissambled it again and everything seems to be okay. I am losing my mind lol. It's on my bed when I work on it, so i don't think it's the stand. When I literally place the top board cover, the ringing is back. It sounds worse when I screw it in place. And it's so weird because it's just the the keys on the middle C that does that >.<

Hi Everyone, I don't know what happened to my keyboard but it just started sounding weird. When I press the keys between the middle C, there's a ringing sound. I disassembled to check if something dropped or if it's dirty, I found nothing lol Weird though, because when the top board is not in placed, it plays okay. It's just when I put it down, the ringing sound can be heard so bad again. You can hear it from this video. Any help would be greatly appreciated