Microwave will not start; display shows E1 when START is pressed.

Safety Warning: Microwaves contain high-voltage components and a high-voltage capacitor that can retain a dangerous charge even when unplugged. If you need to access internal components beyond the control panel or door switches, discharge procedures and professional tools are required. When in doubt, contact a qualified technician.

Step-by-step checks (external first):

• 1. Power reset: Unplug the RCA microwave for 5 minutes, then plug it back in and try again. Sometimes E1 can be a transient door-sensing error.
• 2. Inspect the door: Open and close the door firmly. Check that the door is not sagging and that the latch hooks fully engage the cabinet. Look for cracked or loose plastic around the latch area.
• 3. Listen for clicks: Slowly open and close the door while listening for 2–3 distinct clicks from the interlock switches. If you do not hear them, the switches may be misaligned or broken.

Internal checks (for experienced DIYers only):

• 4. Unplug the unit. Remove the outer cabinet screws and carefully lift off the cover (countertop models) or remove the control panel (OTR models) to access the door switch cluster.
• 5. Inspect switches and bracket: Check the primary and secondary door switches mounted near the latch. Look for burned terminals, loose spade connectors, or a cracked plastic mounting bracket.
• 6. Test with a multimeter: Remove one wire from each switch and test continuity. The normally closed (NC) switch should read continuity with the door closed and open circuit with the door open. The normally open (NO) switch should be the opposite. Replace any switch that does not change state correctly.
• 7. Reassemble and test: Reinstall the switches securely, reassemble the cabinet, plug in, and test operation. If E1 persists, the control board may be misreading the door circuit and should be evaluated by a technician.