¶ Fault Phenomenon
After turning on the printer power, the touchscreen displays an error message: mcu THR : Unable to connect
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¶ Fault Cause
Poor contact of the extruder communication cable
Loose screw securing the extruder communication cable
¶ Tools Required for Troubleshooting
1.5mm hex screwdriver
2.0mm hex screwdriver
¶ Troubleshooting Steps
¶ 1. Check whether the surface of the extruder communication cable is damaged
a. Turn off the printer power switch and unplug the power cord.
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b. Inspect the surface of the extruder communication cable for damage or cracking.
If damage is found, it is recommended to replace the extruder communication cable with a new one. Turn off the printer power and do not use the printer temporarily
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¶ 2.Check whether the connector on the extruder side is loose
a. Turn off the power switch and unplug the power cord.
b. Check whether the two screws securing the extruder communication cable connector are loose. Tighten the screws clockwise.
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c. Check whether the retaining clip is cracked.
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- If the retaining clip is cracked, provide photos and contact technical support to assess the damage
- If the retaining clip is not cracked, remove the screws, re-plug the extruder communication cable connector
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¶ 3.Check whether the connector on the mainboard side is loose
a. Turn off the power switch and unplug the power cord.
b. Use a 2.0mm hex screwdriver to remove the five screws securing the mainboard cover, and slowly open the mainboard cover.
How to open the motherboard cover of Neptune 4 Plus+ & Neptune 4 Max+
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How to open the motherboard cover of Neptune 4 + & Neptune 4 Pro+
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c. Check whether the connector is loose. Re-plug the connector.
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¶ 4.Move the extruder left and right while checking whether the error occurs
a. Plug in the power cord and turn on the printer power switch.
b. Manually move the extruder and check whether the touchscreen displays an error message while moving the extruder.
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- If an error message appears while moving the extruder, the extruder communication cable needs to be replaced.
If you are unsure about the inspection results, please contact the technical support team with the following information. If any component is damaged, take a photo and send it to technical support for evaluation.
- Is the surface of the extruder communication cable damaged?
- Is the connector on the extruder side loose or damaged?
- Is the retaining clip damaged?
- Is the connector on the mainboard side loose or damaged?
- Does the touchscreen display an error message when moving the extruder left and right?
Technical support team email address: 3dp@elegoo.com