Internal speakers aren’t working
the sound on my Mac desktop isn’t working. The system preference says there is no device
iMac 21.5″, macOS 10.15
Frst thing to try...
Have you done a PRAM reset, CMD+Option+p+r...
Reset NVRAM on your Mac - Apple Support
In fact, do 3 in a row, takes a bit of time.
Intel-based Macs: Resetting the System Management Controller (SMC)...
Reset the SMC of your Mac - Apple Support