I have the same case and to be honest the fan controller built in does not give a wide range of speed. I don't know the specifics behind the design but I have 4 scythe ultra kaze fans, 2 listed in my sig, and it would not spool them up to get the full 300 cfm out of them. It would not even push 2 of them at full rpm. What I did was I took a fan with LED's built into them and hooked it up to the 600T controller and turned the knob from high to low and looked for a decrease in the LED light output to tell me that it was actually working. I thought the same, that it didn't work but it in fact does just a very low range of speeds. But if the light dims when you turn the knob, it works as intended. I had to purchase a separate fan controller to get the range I was looking for.
