Please help: chimes on reboot when muted

[WanderingPhilosopher]

I am running El Capitan 10.11.5 on a Mac Mini late 2009. When I need to be quiet, I use the keyboard button to mute the sound before restarting. Unfortunately, the machine chimes anyway, quite loudly. Can anyone tell me what might be going wrong and how to fix it? I'd prefer to avoid messing with scripting in a permanent change if possible. Thank you in advance.

 

[JohnDS]

Try resetting the PRAM by cold booting while holding down the command-option-p-r key combination until you hear the startup chime a third time. Then turn the volume off and reboot.

 

[WanderingPhilosopher]

Try resetting the PRAM by cold booting while holding down the command-option-p-r key combination until you hear the startup chime a third time. Then turn the volume off and reboot.

Thanks, but I tried resetting the PRAM (per Apple's instructions, which was 2 chimes rather than 3), and it didn't work. In fact, as soon as I'd done that, my recurrent wi-fi connectivity issues returned; can't say whether or not there was a connection. Anyone else?