YES, ALL OF THEM ARE DUAL VOLTAGE !!!
All the Power Supply boards are engraved with the input as 100-240v 50/60Hz, so how i decided to plug them directly to 220v athought on the back label marking that it is 110v?, well i also have a Samsung UN46F5500AG (GCFV) sold in Argentina that the label is marked only as 220-240v 50/60Hz, but the power supply boards also is marked as 100-240v, so i plugged it to 110v and turned on fine, that means that is dual voltage.
So if you want to make sure that the power supply of your Samsung TV is dual voltage, open the back cover, and you will see the video board (green one) and the power supply board (orange one), there is a table with some specs and the input must say 100-240v 50/60Hz.
I have 3 Samsung LED TV and the three of them are labeled as 110-120v but the internal power supply boards are marked as Input voltage 100-240v 50/60hz.
Are they really dual voltage?
Power Supply boards for:
UN46ES6150FXZA > BN44-00502A
UN55ES6150FXZA > BN-06430L
UN65HU8500FXZA > BN44-00741A
I can confirm that they only are NTSC for the coaxial input.