Can I move the jumper to 12V to supply more current to a 5V fan without damaging it? I figured my fan will draw 800mA.

Hi, I've had the mx400 for 6 months or so but never got to attaching fans to it. I tried attaching my cpu fan to it and it doesn't seem to provide power when it boots up. Is there anything else I have to connect in order for it to work? Also can it handle high wattage fans? I'm planning to get a ...