not turning on?

i have a zen and it will not turn on at all it worked fine up til about a month ago and i am wondering if anyone has any ideas on how to get it working again or how they can be fixed......i tried the reset button to no prevail and charging it longer ........the screen is completly black like there is no power to it but when plugged in if you put it to your ear you can hear something inside .....if anyone can help i would appreciate it