Here's what the problem was:
Started the 'Normal' cycle... I closed the door... it calls for water, water fills, ECS sensor doesn't kick it to the next segment of the cycle (wash), so the water over-fills and reaches the over-fill sensor.
So many other are replacing the plastic 'case-brake,' main board, and the ECS sensor. I, however, was able to get by with just the ECS sensor replacement, which is known to be a faulty design by Samsung, supposedly.
The idea is replace the (1) most common known issue, which also happens to be (2) the cheapest of the three parts.
Simple... simple... simple.
CUT THE POWER TO THE UNIT. Breaker off!
Tip the unit on its side.
Remove the plastic leak-sensor pan (without unplugging the leak-sensor).
The ECS sensor has a blue wire connected to it. Do a quarter-twist to remove the sensor from the assembly. KEEP THE RUBBER O-RING!!
Put the new sensor in WITH THE OLD O-RING, and plug it up.
Re-attach the leak-sensor pan.
Situate the unit upright, and wash a load, ensuring its completion of a full cycle BEFORE you situate it in the cabinet space.