DX9 not making sound

please excuse my ignorance, im very new to this and have been trying to find out online.

so just checking, if I am measuring the one in the photo… would that mean, that my red pin of my MM is and then i go around with it on the diode setting and check what you wrote in the last post?

https://imgur.com/a/Yq661oh

sorry again for my cringeworthy rookieness here, i’ve been trying to figure out what you meant last few hours with youtube