Microwave displays H98 and will not heat; fan and light may operate but food remains cold.

Critical safety warning: High-voltage components (inverter, capacitor, magnetron) can store lethal charges even when unplugged. Do not attempt high-voltage testing unless you are a trained appliance technician with proper tools and procedures.

• Basic check: Confirm that the turntable, interior light, and fan operate when starting a cook cycle. If they do but there is no heat and H98 appears, the issue is in the high-voltage system.
• Ventilation: Ensure vents are clear; overheating can trip thermal cutouts, but H98 usually indicates a component failure.
• Internal inspection (technician-level): With power disconnected, a technician will inspect the inverter board, magnetron, and associated wiring for burns, arcing, or loose connections.
• Component replacement: Typically, the inverter board and/or magnetron must be replaced as a set if either has failed, using OEM Monogram parts.

Recommendation: Due to the danger of high-voltage exposure, contact an authorized Monogram service provider for H98 errors.