Mini TRS "mini-stereo" cable not working?

Tried to hook up my MacBook Pro and OP-1 using a Mini TRS “mini-stereo” cable. Do MacBook and OP-1 have signal flowing in the corresponding tip/ring/sleeve of the cable? Should this work in theory? Because I can’t get it to work. Faulty cable or something else? Sorry for asking such an idiotic question.

Are you trying to do audio out of the MacBook Pro into the OP-1? because that should work

Yes… probably a faulty cable then. Should return it for a new then…

Have you plugged it into the Red jack on the OP-1 and selected it as your sample source?

CB

Yes… Nothing…

Is the Red input socket on the OP-1 otherwise working? Can you try a mic in it, or some other way to eliminate. The board on the OP-1 which hosts the jack sockets and power switch has had to be replaced by quite a few owners.

CB

This is a brand new unit. First time I’m using the input jack. Would suck if I had to replace it… I’ll check…