Safety first: Disconnect mains power. The selector switch carries mains voltage; handle with care.

Check knob and shaft: Ensure the function knob is not cracked and that it firmly engages the selector shaft. Replace the knob if it slips.
Access selector switch: Remove the control panel to expose the rotary function selector switch.
Inspect for damage: Look for melted plastic, burnt contacts, or loose terminals on the switch.
Test continuity: Using the wiring diagram (often on the rear panel), test continuity between switch terminals in each position. If expected connections are missing, the switch is faulty.
Check wiring: Tighten all spade connectors and ensure wires are in the correct positions according to the diagram.
Replace selector switch: Transfer wires one at a time from the old switch to the new Severin selector to avoid miswiring. Mount the new switch securely.
Test functions: Reassemble, restore power, and test each oven mode (bake, grill, fan) to confirm proper operation and that F5 is cleared.

Oven shows F5, timer works but elements and fan do not start

Possible Causes