After great help from Appliance Parts Pros, used the Tech sheet supplied with range and a good multimeter to identify an open circuit on the BAKING ELEMENT. Thermister tested good, about 1100 ohms at room temperature. Broil Element was good, Controls working properly. This is hard to determine as the broil element comes on during warmup when in regular Baking mode. Could hear both relays clicking when warming up. This model has no convection heating element.
REPLACE BAKING ELEMENT: element is hidden under the floor of the oven, accessible from the rear of the unit. Unplug all power, remove the rear cover of the unit, remove the terminal block from the rear of the unit, disconnect two baking element power leads, remove two #2 Phillips mounting screws, slice the insulation between the two ends of the baking element, and gently slide out old element.
Reverse to install a new one.
Motor Assembly was easy except note that fan retaining nut is left-hand thread--used 9mm socket. It took a few minutes to work off the fan blade, but it did come off without bending any blades
The Appliance Parts Pros I spoke with were very helpful in identifying the particular Samsung Range that I had, a NE59J3421SS/AA Rev2. Parts came amazingly fast. The job took about an hour.