Macbook Pro Late 2011 13" Dual Monitors I have two external monitors (both are Sanyo TVs). My Macbook Pro has one Thunderbolt. I purchased a Mini DisplayPort to Dual HDMI Adapter. The adapter is connected to the Mini Display port and to a USB. I have two HDMI cables, each connected to their own HDMI port in the adapter. My problem: The laptop works just fine independently; however, the two external monitors mirror each other. I have tried clicking on Display and clicking on Detect Displays but it does not detect the 3rd monitor or if it does, I am unable to make it work independent of the 2nd monitor - Help, Please!
Are you able to confirm that your MiniDisplay port to 2x HDMI cable supports two separate outputs and not just mirroring of the output?

If you go to System Preferences : Displays : Arrangement can you see the two monitors?

Can you uncheck the box the says “Mirror Display”?

If you don’t see the two monitors, I’d guess that the adapter is an HDMI splitter and does not support two Independant desktops.