Diagnosis
The burning plastic or electrical smell from your Samsung ME19R7041FS vent fan, distinct from cooking odors, typically indicates something is overheating inside the vent system. The most common cause is a foreign object—like a piece of plastic packaging, a utensil wrapper, or accumulated grease-soaked debris—that has been drawn into the blower housing and is contacting the hot vent motor or, if your model has one, a charcoal filter heating element.
How to Fix It
Immediately stop using the vent fan and unplug the microwave. Remove the grease filters from the underside of the unit. Using a bright flashlight, look deep into the vent cavity toward the blower fan. If you see debris, use long needle-nose pliers or tweezers to carefully extract it. For a more thorough inspection, you may need to remove the internal vent cover by unscrewing it from inside the microwave cavity, but ensure the unit is unplugged first.
If That Didn't Work
If no debris is found, the issue is likely mechanical. A seized or failing vent motor bearing will overheat and produce a distinct burning smell, often accompanied by a loud grinding or whining noise. For this model, replacing the entire vent motor assembly is the required fix. Additionally, if your microwave uses recirculating mode with a charcoal filter, check that the filter is properly installed and not touching any components, as it can overheat.
Heads Up
Continuously operating the fan with this smell poses a serious fire risk and can cause permanent damage to the motor or wiring. If you cannot locate and safely remove the obstruction, or if the motor itself is faulty, discontinue use and contact a qualified technician for service.