There is no thing as a Samsung Roku tv. There are Samsung Smart tv's but they use a different OS for the apps. And some Samsung tv's have a single Roku Ch for free movies and tv shows with ads. What do you have?
As much as myself and I'm sure others here on the forum would love to see a Samsung, LG and Sony Roku TV. Sadly, they don't make these yet. Which is too bad because they would be pretty darn nice.
But I presume that possibly, you may have a Roku Stick or other small stand alone Roku plugged into your Samsung TV and it is not waking up.
This is something that happens a lot. The batteries die, and the Roku not sensing a signal from the remote to awake just keeps on napping away.
The first thing to try is place some brand new batteries into your Roku Remote. And pay very careful attention to the way the (+) Plus and (-) Minus sides of the batteries are lined up correctly when installing them back in the remote.
Roku is my favorite streamer, mkvXstream.com has my favorite Roku channels