LONGER LK5 Pro Full Use Tutorial: Assembly＆Setup Instruction

The LONGER LK5 Pro is a large-format 3D printer designed for reliable and high-quality printing. Whether you are setting up your printer for the first time or troubleshooting a specific issue, this guide covers the complete process from assembly to printing.

Follow the sections below in order to assemble the printer, complete the initial setup, and resolve common problems during daily use.

1. Assemble the Printer

Before powering on the printer, make sure all components are assembled correctly and all cables are securely connected.

Download the Latest Firmware

Download the latest LONGER LK5 Pro firmware here:

https://drive.google.com/drive/folders/1xvMYLhAvwqhYiqoT559U8gBzruGjQ_AE?usp=sharing

Missing Parts

If any parts are missing after unpacking the printer, please contact the LONGER Technical Support Team at support@longer.net. After confirmation, replacement parts will be arranged.

Assembly Tutorial

Follow the official assembly video to complete the printer installation:

https://www.youtube.com/watch?v=F_VzVxOhHSo

2. Power On the Printer

After assembly, turn on the printer and verify that all components are working properly.

Touch Screen Does Not Turn On

If the touchscreen remains blank after powering on:

• Verify that the input voltage matches your local power supply.
• Check whether the touchscreen cable is connected correctly.
• If the issue persists, inspect the power indicator and mainboard indicator by removing the bottom protective cover.

Video tutorial: https://www.youtube.com/watch?v=K8Jwu-faDfQ

Fan Noise or Abnormal Sound

If the cooling fan produces unusual noise:

• Check whether the fan blades are damaged.
• Remove any foreign objects that may block the fan.

If necessary, take photos of the fan and send them to support@longer.net for further assistance.

3. Level the Print Bed

Proper bed leveling is essential for successful first-layer adhesion and print quality.

The recommended distance between the nozzle and the print bed is 0.1–0.2 mm, approximately the thickness of a sheet of A4 paper.

Follow the official bed leveling tutorial:

https://www.youtube.com/watch?v=TJ0MOFPuOTQ

If the printer still cannot be leveled correctly:

• Place the glass bed and aluminum plate on a flat surface.
• Check whether the heat bed is bent or warped.

If the heat bed is damaged, contact the LONGER Technical Support Team.

4. Zeroing failed

Failed to return to zero/abnormal noise of return to zero/impact limit still does not stop motion. Please check whether the limit switch is complete and the installation condition, and follow the video: https://www.youtube.com/watch?v=m3sQGZVFDqY , check the cable installation condition.

About the Z-axis limit switch height adjustment, refer to the video in the link below.
https://youtu.be/F_VzVxOhHSo?t=255

5. Load/unload filament

Error8

Check the real-time hot-end temperature display on the screen. If it is negative, check the installation of the thermistor plug; make sure it is installed as below:

If anything good about thermistor, that is hot end issue, in this case we should follow the below video to change hot end: https://www.youtube.com/watch?v=RwpLTFwFzAg

Error0 or Error12

Check the installation of the hot-end thermistor and the plug of the hot-end heating rod.
If the installation is normal, the cable may be broken. Replace the hot end;

The extruder is not working

• Check the installation of the extruder cable plug (E refers to the extruder).
  
• The extruder defaults to work after reaching the hot end set temperature (minimum 195 degrees). If it still cannot work, check the installation of the extruder motor wire.
  
• If it still can't work, exchange the X and E motor wire plugs, control the movement respectively, and report the situation to the after-sale service.

Filament cannot be extruded

When, without loading the filament, the extruder works fine, this situation is a hot end block. When the filament is not loaded, the extruder works abnormally; please contact the after-sales service directly support@longer.net

Nozzle smoking

Check the thermistor is completely detached or loosely installed (check when cooling); reinstall it.

6. Start printing

After loading the filament and leveling the print bed, you are ready to start printing. If you encounter any of the following issues, refer to the corresponding solutions.

Micro SD Card Is Not Recognized

If the printer cannot detect the Micro SD card:

• Format the Micro SD card using the recommended formatting tool.
• Copy the required files back to the card.
• Clean the SD card contacts with alcohol, allow them to dry completely, then reinsert the card and restart the printer.

Micro SD Card Formatting Tool

https://drive.google.com/drive/folders/1TgCT1CBsjI4-7prSu1nEUXxQ6vhsJzms?usp=sharing

Preloaded Micro SD Files

https://drive.google.com/drive/folders/1zz5mlLMBoa3DguuyG6YDHJJXnhL-XKnJ?usp=sharing

Newly added files not recognized

The LONGER LK5 Pro only recognizes G-code files stored in the root directory of the Micro SD card.

If newly added files do not appear:

• Make sure the file is in G-code format.
• Save the file in the root directory instead of a folder.
• Generate the file using compatible slicing software.

Error 9

If the hot bed temperature displayed on the touchscreen is negative:

• Check whether the heat bed cable is connected correctly.
• Measure the resistance of the aluminum heat bed using a multimeter.

Video tutorial: https://www.youtube.com/watch?v=yFV3JCilzA8

Error 1/13

• Check the heat bed cable connection.
• Measure the resistance of the aluminum heat bed.
• If the resistance is normal, replace the cable for testing.

The print size is too small

If the printed model is smaller than expected:

• Verify the model size in your slicing software.
• Check that the correct printer profile is selected.
• If the settings are correct, verify the printer firmware version.

Firmware Download

https://drive.google.com/file/d/1rRos32XckF5ZlI5tYlCTlyt22E_BlQXP/view?usp=sharing

Firmware Update Guide

https://www.longer3d.com/blogs/academy/longer-lk5-pro-full-use-tutorial

Filament not sticking to platform

Poor first-layer adhesion is usually caused by incorrect bed leveling or slicing settings. Try the following:

• Use the default LONGER Cura print profile.
• Re-level the print bed.
• Keep the nozzle approximately one sheet of A4 paper above the bed.
• Enable a Raft when slicing the model if necessary.

Bed leveling tutorial: https://www.youtube.com/watch?v=TJ0MOFPuOTQ

If the problem persists, check whether the heat bed is bent.

Filament not extruded

If filament is not feeding during printing:

1. Check whether the drive gear is securely fastened to the extruder motor shaft.
2. If the extruder motor does not rotate, test the motor by following the official video: https://www.youtube.com/watch?v=XCjrieoyZ1c

3. Make sure the nozzle is not too close to the print bed.
4. If the hot end is clogged, inspect or replace it as described in the previous section.

7. Other issue

Incorrect Firmware

Installing the wrong firmware may cause abnormal printer behavior.

Download the correct LK5 Pro firmware and follow the official update guide:

Firmware Download：

https://drive.google.com/file/d/1rRos32XckF5ZlI5tYlCTlyt22E_BlQXP/view?usp=sharing

Firmware Update Tutorial：

https://www.longer3d.com/blogs/academy/longer-lk5-pro-full-use-tutorial

"Resume Printing" Message Appears Repeatedly

If the printer repeatedly displays "Resume Printing" even though the power supply is normal, update the printer to the Marlin 2.0 firmware.

Marlin 2.0 Firmware

https://drive.google.com/file/d/10mY1k7CIIJYEa2HbqzdXNSre7h4x6Zfa/view?usp=sharing

After updating the firmware, restart the printer and check whether the issue has been resolved.

Printer Stuck on the Startup Screen

If the touchscreen remains on the startup screen and the firmware cannot be loaded:

• Check whether the touchscreen cable is connected securely.
• If the cable is connected correctly and the problem continues, contact the LONGER Technical Support Team for further assistance.

Need More Help

If the issue cannot be resolved after following the steps in this guide, contact the LONGER Technical Support Team at support@longer.net.

To help us diagnose the issue more quickly, please include:

• Printer model
• Firmware version (if available)
• Error code or error message
• Photos or videos of the issue
• The troubleshooting steps you have already completed