• [ ] Photograph the printer from all sides.
• [ ] Photograph wiring before disconnecting anything.
• [ ] Label motor, heater, thermistor, fan, probe, and endstop connectors.
• [ ] Record board model and firmware.
• [ ] Inspect frame, joints, wheels/rails, belts, and leadscrews.
• [ ] Check power supply rating and wiring condition.
• [ ] Gather the correct tools and replacement hardware.

• [ ] Frame is square and fasteners are secure.
• [ ] Gantry moves smoothly through its full travel.
• [ ] Belts are aligned and tensioned evenly.
• [ ] Leadscrews are clean, aligned, and supported.
• [ ] Bed moves freely without binding.
• [ ] Wiring is secured away from moving and hot parts.
• [ ] Fans are oriented correctly.
• [ ] Heater and thermistor wiring is secure.
• [ ] Grounding and mains wiring have been inspected.

• [ ] Verify supply voltage selection before powering on.
• [ ] Confirm no exposed conductors or loose strands.
• [ ] Power on with hands clear of moving parts.
• [ ] Verify display/controller startup.
• [ ] Test each fan and motor separately.
• [ ] Verify temperature readings are plausible at room temperature.
• [ ] Test endstops/probe before homing.
• [ ] Keep an emergency power disconnect accessible.

Safety: Disconnect mains power before electrical work. If mains wiring, grounding, or supply voltage is uncertain, have a qualified person inspect it.