@ndk1979 please provide the information as requested here: https://retropie.org.uk/forum/topic/3/read-this-first

As you can see, people are trying to help but having to guess at how you've configured your setup and how you're running the game, and with what emulator. If you can give us more information it will enable us to assist better.

@challenger2010 said in No sound at all in Mortal Kombat 2/3/Ultimate:

I remember long ago that with Midway games in Mame, you had to go into the service menu of the game and turn the volume up.

This is right as the default volume is quit low on these machines.
But in the end you should hear something (very quit...but no silence at all), and the author mentoined that he allready used the volume control in the service menu ("F2").

Just to mention it: AdvanceMame has this great feature "auto level volume" which prevents me from running to the volume control on my setup as i dont have a remote control for my 2.1 logitech-soundsystem :)