Microwave will not start; display shows E1 immediately after pressing Start.

Safety first: Unplug the microwave from the mains. Microwaves contain a high-voltage capacitor that can retain a dangerous charge even when unplugged. Do not touch any high-voltage components (capacitor, transformer, magnetron). If you are not experienced, contact a qualified appliance technician.

Step-by-step checks:

• 1. Inspect the door: Check that the Salter microwave door closes fully and evenly. Look for bent or worn plastic latch hooks on the door. If the hooks do not fully engage the cabinet, the interlock switches will not actuate.
• 2. Clean the latch area: Food debris or grease around the latch openings can prevent full engagement. Clean the latch openings on the cabinet with a damp cloth and mild detergent, then dry thoroughly.
• 3. Check for door play: Gently lift the door up and down. Excessive play can indicate a worn door hinge or loose hinge screws. Tighten accessible hinge screws on the outer cabinet if possible (do not remove the internal shielding).
• 4. Switch continuity test (advanced): With the outer cover removed (only if you are competent and after discharging the capacitor), locate the door interlock switch cluster near the latch openings. On most Salter countertop microwaves this includes a primary interlock switch and a secondary interlock/monitor switch. Using a multimeter, test each switch for proper continuity when the door is opened and closed. Replace any switch that does not change state correctly.
• 5. Replace faulty switch assembly: If a switch is defective or the mounting bracket is cracked, replace the door interlock switch or the complete door switch assembly with a compatible Salter part. Reassemble carefully, ensuring all shielding and screws are refitted.

If E1 persists after confirming the door closes correctly and switches are replaced, stop using the microwave and consult a professional technician.