Microphone not detected when webcam removed

i use a headphones with built in microphone now when the webcam is connected the microphone works fine but when webcam is removed microphone is not detected . i have dell inspiron 3647 pc
inxi -Fazy System: Kernel: 5.10.49-1-MANJARO x86_64 bits: 64 compiler: gcc v: 11.1.0 - Pastebin.com
pacmd -list-cards <pre>2 card(s) available. index: 0 name: &lt;alsa_card.pci-0000_00_03.0&g - Pastebin.com