Emergency stop button

The red mushroom-shaped safety switch, mounted under the display on the panel box at the front of the machine. It cuts power to active components (motors, heaters) immediately when pressed.

What it looks like

A large red button with a wide round head, mounted under the display, on the panel box at the front of the machine. When released, the head sits clearly raised above the housing. When pressed, the head sinks flush and locks in place.

How it works

It’s a rotary latch switch: pressing it locks it down; it must be rotated clockwise to release. It interrupts the safety circuit physically, not just a signal — meaning even firmware can’t override it.

Procedures

Releasing the button (after pressing)

1. Grip the red head firmly.
2. Rotate it clockwise (as if unscrewing a jar lid).
3. The button pops up with a soft click.
4. Verify it is fully extended — not stuck in an intermediate position.
5. If the machine was on when the button was pressed, run Firmware Restart from the Klipper / Mainsail interface to bring it back online.

Pressing the button (emergency)

1. Hit it firmly with the palm of your hand.
2. It locks down automatically — no need to hold it.
3. The machine cuts power immediately.

When to suspect the button is pressed

• The machine doesn’t respond to commands at all
• Display is on but motion is dead
• Firmware Restart has no effect
• Customer says: “It was working, then suddenly nothing”
• After moving the machine: the button can be pressed accidentally during transport

Safety notes

• The button is a certified industrial safety component (Cat. 1 or higher)
• It must never be bypassed — it is part of CE/safety compliance
• Replace only with an equivalent certified part if damaged

Related notes

• Machine won’t start - emergency button — the most common “why won’t it start” issue
• Firmware restart — how to restart Klipper after release
• Power outlets (power box)
• Panel Box wiring