I had the same problem and I solved it. I thought that the problem is that the control unit does not remember the color settings. I set the color manally, then switched my computer off, than swithed it on and the lights were powered off. The fans were spinning normally but there were no lights. I have advanced fan controller (aquaero 6). I can choose one of three control mode. Power mode (the fan speed is controlled only by voltage level), the Speed mode (the fan speed is controlled by software using voltage) and the PWM. I used Speed mode all the time. Then I read that the problem is caused by unsifficient power so I switched to Power mode and set manually the max power (11.8 V). I set the color, switch my PC off and the on but still no lights. So I opened the aquaero SW tool again and switched to PWM and the LEDs were immediately powered on and the there were the color I set last time. So no problem with memorizing the color or unsufficient power. You just need to switch the control mode to PWM on you motherboard (or whatever fan controller you use). And don't remember to use 4-pin cable
