AV Out will not work correctly on WDTV Live

As has been said it looks like the player is set to the wrong TV standard. You need to change it to PAL or NTSC depending on where you live. If you go to the setup page for video you can change it directly without resorting to the reset switch, you should be able to see it even with your current problem. Out of interest and for future reference you have a Live Streaming player gen3, this part of the forum is for the older live and live plus.
If you do use the reset button then don’t forget to hold in the button for at least 10 seconds, with the player fully booted up, and then release it