Crossfire 160 GB external hard drive

Question

My computer won't recognize my hard drive anymore. I plug it in and nothing happens. When I turn the switch on the back of hard drive on it beeps like an alarm or something, but it's very quiet. Also the green light on top flashes, in one long flash and 5 repeated short flashes. I've been loading movies on it and it's been working fine and then it just quit one day and it's not even close to being full.