Microwave displays E08 and may shut down mid-cycle, especially on high power.

Safety warning: Work on live mains connections must only be performed by qualified personnel. Do not open the appliance cabinet to access the mains terminal block unless you are properly trained.

User-level checks:

• 1. Check outlet: Plug another high-power appliance (e.g., an electric kettle) into the same outlet to verify it supplies stable power.
• 2. Avoid extension leads: Connect the Siemens microwave directly to a wall outlet. Long or undersized extension cords can cause a significant voltage drop.
• 3. Reset power: Unplug the microwave for 5 minutes, then reconnect and test.
• 4. Check for overload: Ensure the microwave is not sharing an electrical circuit with multiple heavy-load appliances that could cause voltage dips.

Technician-level:

• Measure mains voltage under load.
• Inspect and tighten the internal mains connection block.
• Test the power supply/filter PCB and replace if found defective.

If E08 recurs and your household voltage is normal, the internal power supply board likely requires replacement.