Microwave shows E12 and the interior light and fan may run, but no heating occurs in any mode.

Safety: Unplug the microwave. Work on the control board only if you are experienced with electronics.

Basic confirmation:

• Verify that the unit counts down time and appears to run, but food remains cold in all modes.
• Listen for the usual click of relays when starting a cycle; absence of clicks may indicate relay failure.

Control board inspection (qualified):

• Remove the control panel and inspect the main PCB.
• Look for burned or cracked solder joints around the power relays and triacs.
• Check for discoloration or melted plastic on relays.
• Test relay coil resistance and verify switching (using safe bench methods).

In most cases, the entire control board is replaced rather than individual components, following Fagor service procedures. Due to the integration with safety circuits, board-level repair is recommended only for professionals.