Burning smell during operation, sometimes accompanied by smoke from vents.

Safety first: Immediately unplug the machine. Do not continue using it until the cause is found.

Inspection:

• Check for spills: Look for burnt coffee or milk residues on the thermoblock or heater. Clean carefully once cool.
• Inspect wiring: Open the housing and look for melted insulation, burnt connectors, or scorched PCB areas. Replace damaged wiring and connectors.
• Ventilation: Ensure vents are clear of dust and obstructions.
• Component failure: If a specific component (pump, motor, heater) smells burnt or is discolored, replace it before further use.

Warning: If you see smoke from the electronics, the control board likely needs replacement by a professional.