Sharp Microwave Secondary interlock switch / door-sensing switch; also identified in some Sharp documentation as a damper, primary interlock, or third-door switch QSW-MA168WRZZ

Sharp OEM microwave safety interlock switch used for door sensing and interlock control. The exact function label varies by microwave model and service documentation.

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Common Symptoms

• Microwave does not start or intermittently starts only after the door/drawer is fully latched.
• A fuse may open during door/drawer operation when an interlock fault is present.
• If cooking does not stop when the door/drawer opens, discontinue use immediately; the interlock system requires qualified service.

Check Before Replacing

• With power disconnected, inspect only externally accessible door/drawer latch areas for obstruction, damage, or abnormal looseness; do not remove the outer case or touch internal wiring.
• Confirm the door or drawer closes, latches, and opens smoothly. The applicable service procedure requires correct latch-hook alignment for the interlock switches to actuate.
• Do not attempt energized continuity testing or bypass any microwave safety switch. A qualified technician should verify switch sequencing, continuity, latch adjustment, and post-service microwave-leakage compliance using the model-specific service information.

Pro Tip

Part Details

Key Features

• Genuine Sharp microwave switch part number QSW-MA168WRZZ.
• Documented as a secondary interlock/door-sensing switch in Sharp microwave-drawer documentation.
• Also documented in certain Sharp models as a primary interlock, third-door/door-sensing, or damper switch.
• Part of the microwave safety-interlock system, which is intended to de-energize cooking-related circuits when the door or drawer is opened.

Installation Notes

• Microwave servicing exposes high-voltage components and requires qualified-service procedures; do not open the cabinet for DIY replacement.
• Use the service documentation for the exact model because QSW-MA168WRZZ may be installed in different interlock or damper-switch locations.
• The Sharp service procedure calls for correct latch-hook/switch alignment and verification of monitor/interlock operation after reassembly.
• After any door, drawer, latch, or interlock servicing, the applicable Sharp procedure requires a microwave-leakage check with an approved survey meter.

Verified Compatible Models

KB6524PS, KB6525PS, R1881LSY, SMC1585BB, SMC1585BS, SMC1585BW, SMD2470AH, SMD2470AS, SMD2470ASY, SMD2477AHC, SMD2480CS, SMD2480CSC, SMD2489ES, SMD3070AS, SMD3070ASY

Fitment reminder: Match the complete appliance model number, including suffix or revision where applicable, before ordering.