Jacob,
I would imagine the "black box" is the container that holds the ballasts. It is probably the Hamilton light setup. From the sound of it it has three MH and a VHO setup all together with a reflector.
The pins are the connectors from the light sockets to the ballasts.
From what you are describing, one of the MH ballast is bad. Just make sure it is not the VHO connection.
Pic would be helpful.