#920 Back Cover Opened

Description

#920 indicates an error that the back cover is opened during a task, so the task is forced to stop.
The laser tube is in the chamber at the back of the machine, and the back cover must be closed for safety reasons. A weak magnet, faulty back sensor, etc, can cause the issue. Please follow the instructions below to find the root cause.

Possible Causes

Step 1

• Ensure the back cover is installed securely and the screws are screwed firmly.
  (Reinstall the back cover if necessary.)

Determine your result and the next action to take:

Step 2

Close the door and check whether the back cover icon in Control mode is open or closed.

Determine your result and the next action to take:

Step 3

For safety, please set the power rate to 0% to prevent any laser pulses during testing.

Determine your result and the next action to take:

Step 4

Remove the back cover.

There are two magnets on the back cover.

Determine your result and the next action to take:

Step 5

This step will guide you through testing whether the back cover sensor works normally using the cone spacer

• Find the sensor.

• The back cover sensor will have two white LED lights. They will only light up when detecting magnets.
  

• Place two external magnets close to both LED lights. The light should light up when it detects a magnet.
  One sensor is detecting "N pole" only, meaning that when the N pole of the magnet is close to it, it will light up. The other sensor is detecting "S pole" only.
  
  When both LEDs detect magnets simultaneously, a door-closed signal will be delivered to the system, and the icon on the panel will be changed.

  Make sure the magnets will be above the sensor and the small PCB board. The magnets must not be in contact with components on the PCB.
  
   

Determine your result and the next action to take:

Step 6

Remove the cable of the sensor and check the icon.
When the sensor is disconnected from the system(mainboard), the icon should always stay "Open".

• Turn off the machine and unplug the cable.

• Turn on the machine and go to "Control", wait til the homing finishes, and check the icon.

  

  

Determine your result and the next action to take:

Step 6.1

Replug the cable and re-test with the magnets again.

• Turn off the machine, replug the cable, and turn on the machine.
  

• Put two of the magnets on the sensor's LED lights.
  The light should be "brighter" when it detects a magnet.
  

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• Go to "Control", wait til the homing finishes, and check the icon.

  

  

Determine your result and the next action to take:

Step 7

Update the Firmware to a stable version. Please refer to the link below.
4-7 Firmware Update
 

• Put two of the magnets on the sensor's LED lights.
  The light should be "brighter" when it detects a magnet.
  

• Go to "Control", wait til the homing finishes, and check the icon.

  

  

Determine your result and the next action to take:

Step 8

Check the position of the sensor; the sensor may be mispositioned or have fallen off, which may cause the detection of magnets to fail.  Please check if the screws are firmly screwed and the sensor is positioned straight.

Determine your result and the next action to take:

Step 8.1

Reposition the sensor by screwing the two screws and nuts firmly.

Step 9

Remove the magnets and close the back cover to check the icon's status.

• Remove the magnets from the sensor.
  

• Reinstall the back cover.

• The door icon should be closed when the cover closes and open when the cover opens.

  

  

Determine your result and the next action to take: