Good news, I managed to resolve this with a new cable/adapter. I previously had a moshi mini displayport to hdmi adapter and a certified HDMI cable which I replaced with a single cable comprising both (like this: http://www.jaycar.com.au/p/WQ7442). As I mentioned, the moshi had worked fine for both my macbook pro and mini on Sony tv and monitor, just not the samsung smart tv.
For reference, this was the note from the samsung support team -
1. Use an HDMI cable with a thickness of 14 mm or less. Using a non-certified HDMI cable may result in a blank screen or a connection error.
Some HDMI cables and devices may not be compatible with the TV due to different HDMI specifications.
2. This TV does not support HDMI Ethernet Channel. Ethernet is a LAN (Local Area Network) built on coaxial cables standardised by the IEEE.
3. Some computers do not support HDMI interface, depending on its graphics adapter specifications. In this case, use a DVI-to-HDMI cable to connect the computer to the TV.
4. Try to adjust the resolution of your Mac to 1920 x 1080, which is the maximum resolution of this TV model.
5. Select the connected Mac using the Source button on your TV remote.
Good luck
