I have a 2010 Macbook Pro and recently I bought an LG monitor so I could use it on a bigger screen. However it does not connect to the monitor. I have a computer to HDMI connector and i plugged that in.... than plugged an hdmi cable from the addaptor to the monitor? The macbook screen just flashes blue and on the LG screen it just says HDMI power saving mode. I dont get this? It works perfectly with my XBOX 360? So what am I doing wrong?