I am not familiar with the Samsung head unit. Manufactures often install a fuse, most common inside the unit. Since you consider the head unit as garbage, there is no harm in opening it up (unplugged of coarse) and take a peak inside. Look where the power cord comes in and look for something like this.
If it has one and it looks like this, you are in-luck. Pop it out with a tiny screw driver and read the numbers stamped on the metal portion. Then go to an auto parts store or Radio Shack store for a $1 replacement.
There are many styles of fuses. You might not recognize it. In Google, type "fuse on circuit board" and then click on "images" to see many different styles of fuses. A fuse outside the unit could be flush with the back wall. You might need to twist or pop open a cover to access it. To be honest, it is very rare to find a fuse accessible from the outside these days. If there is one, it is most likely inside, mounted on the circuit board.
I hope you decide to open up the box, look for a fuse, and report back. If you are totally lost at what you are looking for, but are good with a camera and posting pictures, take a good picture of the circuit board for us to review here.
The fuse is the primary line of defense in protection. If there is a problem with the internal circuitry of the Samsung, a replacement fuse will burn up as well. So then throw it away. But if everything works well again, you can assume there was a one time power surge from the motor home that caused the fuse to burn.
Consider this a new "Adventure Anywhere"