Microwave will not start; display shows E01 immediately after pressing START

Safety Warning: Microwaves contain high-voltage components and a high-voltage capacitor that can retain a dangerous charge even when unplugged. If you are not experienced with microwave repair, contact a qualified technician. Never run the unit with the cover removed.

Basic checks you can do safely:

• Unplug the microwave from the wall outlet.
• Open and close the door several times, listening for distinct clicks from the latch area. If the door feels loose or does not latch firmly, inspect the door hooks for damage or obstruction.
• Check that the oven cavity front frame and door are not bent or warped. If the door is misaligned, gently press around the perimeter to see if it seats more firmly.
• Try a different outlet to rule out power supply issues.

Technical inspection (for trained persons only):

• Remove the outer cabinet (after unplugging) to access the door interlock switch assembly on the right side of the cavity.
• Using an insulated multimeter, test continuity of the primary, secondary, and monitor door switches while opening and closing the door. Replace any switch that does not change state correctly.
• Inspect the door latch bracket and actuator levers for cracks or deformation; replace if worn.

If any door switch or latch component is defective, replace the entire door switch assembly or individual switches with OEM Summit-compatible parts. Reassemble the unit and test operation with a cup of water.