How To Turn On Dreamcast VMU Memory Card?

I have just recently got a VMU memory card for my Dreamcast. My question is how do i turn on the Dreamcast VMU memory card? Its not working and there is nothing on the screen display?

You can't turn on the Dreamcast VMU memory card there is no power button for that purpose. If its not switching on, trying replacing the battery inside it. 

Here is an article that will help you with replacing the battery inside your Dreamcast VMU