is there a thunderbolt to hdmi adapter ebay

However, as my partner's Air only has a thunderbolt port and no HDMI port it still doesn't work with her MAC. This is sort of fine for my MBP as I had nothing working before but it seems a bit pointless having the HDMI cable plugged in as well as I might as well just use this in the first place. It seems that there needs to be either a base signal or an earthing through the MacBook Pro's HDMI port for it to switch into an external monitor mode that will detect a thunderbolt to HDMI connection. However, if I then unplug the HDMI cable from MBP or the amp, the thunderbolt port stops working as well and the TV displays 'no signal detected'. I checked that the correct hdmi port was selected on the TV for the direct connection and I could even turn off my amplifier to make sure that I was not seeing the wrong signal and it still worked as long as the hdmi-to-hdmi was still connected at both ends. But if I then plug a normal hdmi-to-hdmi cable from my amplifier to the Mac Pro's HDMI port, suddenly the thunderbolt cable works and the Display Preferences sees the LGTV.

However, if I plug the cable from my MBP directly to the TV HDMI and select that corresponding HDMI port on the TV initially still nothing.

I also tried from the MBP to the HDMI port on the amplifier of the surround sound system and again nothing.

I plugged the cable from my MBP direct to the HDMI port on the TV and nothing, no signal detected.

So a bit of playing around and this is what I found. When the cable arrived, it would not detect our LG TV from either computer. I bought a thunderbolt to HDMI cable from eBay so my partner could plug her Air into the TV. I have a Mac Book Pro, my partner a Mac Book Air. I am having the same problem as a lot of people with Yosemite and and connecting to a TV/external monitor via thunderbolt to HDMI but have found a sort of a solution or at least a bit more info that might lead to someone having a eureka moment.

Is there a thunderbolt to hdmi adapter ebay