Why is the thunderbolt port not reading my FW External HD?

I have an Apple Thunderbolt to Firewire 800 adapter that I use to plug in an external hard drive. When connected and the HD is turned on it does not show up on my system or system profiler.

However when I used the same adapter and ext. HD on my Macbook Air, the drive shows up without any issues.

I have tried to reset the system by unplugging all connections included the plug itself and holding the power button for 20 seconds then rebooting but this has not helped?

Someone mentioned to me that it may be the logic board itself. Can anyone assist in resolving this issue?