after self-cleaning, my oven won't turn on and the display is completely blank.

Diagnosis

The complete loss of power to the display and oven functions following a self-cleaning cycle on the Maytag MER7700LZ is almost always caused by a tripped thermal fuse (also known as a high-limit thermostat). During the self-clean process, the oven reaches temperatures exceeding 800°F. If the internal cooling fan fails or if there is an airflow obstruction, the heat builds up around the control electronics and safety sensors. To prevent a catastrophic fire or the melting of the wiring harness, the thermal fuse is designed to "blow" or open the circuit permanently once a specific temperature threshold is crossed. Because this is a safety device, it cannot be reset like a standard circuit breaker; once it pops, the electrical path is physically severed. You can confirm this diagnosis by attempting to turn on the stovetop burners. On the MER7700LZ, the stovetop elements usually operate on a separate circuit path from the oven controls. If the burners work but the display is dead and the oven won't heat, the thermal fuse is the primary culprit. If the entire unit—including the burners—is dead, the issue likely lies with the main 40-amp or 50-amp double-pole breaker in your home's electrical panel.

How to Fix It

To resolve this, you must replace the blown thermal fuse. This is a hardware replacement, not a software reset.

1. Shut off power to the range at the main circuit breaker panel. Do not rely on the power button; the unit must be completely disconnected from the 240V source to avoid electric shock.
2. Remove the oven racks and the bottom broiler drawer to gain access to the interior chassis.
3. Locate the thermal fuse. On the MER7700LZ, it is typically mounted to the rear oven cavity wall or integrated into the backguard area near the oven vent. It looks like a small white or silver cylinder with two wires attached via spade connectors.
4. Disconnect the two wires from the fuse. Use a digital multimeter set to the Continuity (Ω) setting. Touch the probes to the two terminals of the fuse.
5. If the multimeter shows "OL" (Open Line) or no continuity, the fuse is blown. If it shows a low resistance (near 0 ohms), the fuse is functional and the problem is elsewhere.
6. Remove the mounting screw and pull the old fuse out. Install a genuine Maytag replacement thermal fuse (ensure the part number matches exactly to maintain the correct temperature trip point).
7. Reattach the spade connectors firmly and reinstall the mounting screw.
8. Slide the broiler drawer back in and restore power at the breaker. The display should initialize immediately.

If That Didn't Work

• Inspect the Electronic Control Board (ERC): If the fuse is intact but the display remains blank, the high heat may have scorched the main control board. Remove the backguard panel and look for "burnt" spots or bulging capacitors on the circuit board. If you see black carbon scoring, the board must be replaced.
• Check the Main Power Cord and Terminal Block: High-heat cycles can occasionally cause a loose connection at the rear terminal block to arc or burn out. Inspect the 4-wire connection at the back of the range for melted insulation or charred screws.
• Test the Door Lock Assembly: If the display is on but the oven won't start, the self-clean cycle may have jammed the door lock mechanism. If the lock motor didn't fully retract, the oven will enter a safety lockout mode. Manually inspect the latch for debris or bent metal.
• Verify the House Breaker: Sometimes the massive current draw of a self-clean cycle trips one leg of a double-pole breaker. Even if the breaker looks "On," flip it completely "Off" and then back "On" to ensure both poles are engaged.

Heads Up

• Avoid Frequent Self-Cleaning: Overusing the self-clean feature on the MER7700LZ puts immense stress on the control board and thermal fuses. Consider using a vinegar-and-baking-soda scrub for routine cleaning to extend the life of your electronics.
• Ensure Proper Venting: Never block the oven vents or store flammable items (like plastic trays) too close to the rear of the range, as this restricts airflow and increases the likelihood of the thermal fuse blowing.
• Use Genuine Parts: Always use OEM Maytag thermal fuses. Generic "universal" fuses often have different temperature ratings, which could either blow too early or, more dangerously, fail to blow during a real overheat event.
• Check the Cooling Fan: While the oven is heating, listen for the cooling fan. If you don't hear it running, the fan motor may have failed, which is the root cause of the fuse blowing.