Microwave stops mid‑cycle and displays F04; sometimes accompanied by a loud humming or buzzing noise before shutdown.

Safety first: Unplug the microwave immediately if you hear loud humming or smell burning. Do not attempt to restart it.

• Step 1 – Do not repeatedly reset: Repeatedly trying to run the microwave can further damage the transformer or wiring.
• Step 2 – Visual inspection (unplugged): Remove the outer cover and look for burn marks, melted insulation, or a cracked capacitor in the high‑voltage section. Do not touch the capacitor or HV wiring.
• Step 3 – Check for obvious arcing: Inspect around the waveguide cover and magnetron antenna for signs of arcing or burnt food deposits that could cause internal shorts.
• Step 4 – Professional repair: A technician will discharge the capacitor and test the HV diode, capacitor, magnetron, and transformer. Any shorted component must be replaced with the correct Indesit part. The control board may also be checked for damage.

Warning: This is a high‑risk repair. Do not attempt component testing in the high‑voltage circuit without proper training.