Have tried 2 different sets of "gaming" earbuds with plug-in mic on my PC and neither work. Both used a splitter to separate the mic and speaker plugs. An old headset with separate plugs (made for PC) works just fine.
Issue has to be with either the splitters or the earbud connection to them. Test them on another system with dual plugs see if they work there. Make sure you have things connected properly, a lot of people end up just not having them connected all the way.