Display shows E05; unit may not power on fully or shuts off unexpectedly when heating.

Safety first: Unplug the air fryer. Do not attempt live voltage measurements unless you are trained and using appropriate insulated tools.

Initial checks:

• 1. Outlet and cord: Test the wall outlet with another high‑load appliance. Inspect the Bosch air fryer power cord for cuts, kinks, or burn marks. Replace the cord if damaged.
• 2. Plug seating: Ensure the plug is fully inserted and not loose in the socket. Avoid using low‑quality extension cords or power strips.

Internal checks (advanced):

• 3. Access power entry: Remove the bottom or rear cover to inspect the mains input, line filter, and power supply section on the control board.
• 4. Visual inspection: Look for burnt components, cracked solder joints, or a blown MOV (varistor). Check the main fuse on the PCB; replace only with the same rating if blown, and investigate the cause.
• 5. Voltage regulator: If equipped, check the low‑voltage regulator IC and associated capacitors for bulging or leakage. A failing regulator can cause E05 and random shutdowns.

Recommendation: Because the power supply is directly connected to mains, replacement of the entire control / power board is usually safer than component‑level repair for non‑professionals.