OK, I'm no noob, so I know the thing is set-up right, unless there's a requirement I'm missing. I created the TU Mine via the Latos I-8 station mission. Loaded into a RagIII, set the fire key via Groups. Grid is fine, plenty of power.

Does not launch a mine. Mine quantity shows "1" in the HUD like it's supposed to, but no mine launches when I press the fire key.

Anyone else?

It requires 550 energy, load a Heavy Cell.

Ah, missed the energy to launch requirement. Will do.

ShankTank's solution is the correct one. Although the TU Mine description does not list 550 energy as a requirement for launching, it does indeed require a Heavy Cell to do its thing.