¶ 💡 Compatibility
This guide applies to the following device. Please note when referencing:
- Machine model: U1
¶ ⏰ When to Use This Guide
- The screen shows the error message: “System Failed to Start. No toolhead detected.”
- The screen displays error code: 0003-0522-0100-0006
¶ 📋 Quick Info Card
Difficulty: ⭐⭐⭐☆☆ (Medium)
Estimated Time: 10–30 minutes
Required Skills: Basic cable inspection skills
¶ 🔍 Quick Diagnosis
Which situation are you experiencing?
- All toolhead indicator lights are off → Go to Scenario 1
- Toolhead indicator lights are on → Go to Scenario 2
¶ 🔧 Preparation
¶ Required Tools
- H2.0 hex key
- Multimeter (if available and you know how to use it)
¶ ⚠️ Important Notes
- Always power off the machine before performing inspections or reconnecting cables.
- Using incorrect screw specifications or over-tightening screws may damage the Toolhead PCB.
¶ 🛠️ Troubleshooting Steps
¶ Scenario 1: All four toolhead indicator lights are off
¶ Step 1. Check whether capacitors on the Toolhead PCB are pressed or pierced by screws
If a capacitor on the Toolhead PCB is pressed or pierced by a screw, it can cause an internal short circuit. The machine will enter protection mode and stop supplying power to the toolhead, resulting in all toolhead indicator lights being off.
This issue may occur when fixing the USB cable with an incorrect screw type or excessive tightening force, which can damage the capacitor beneath the screw. Follow the steps below to check:
(1) Use an H2.0 hex key to remove the three screws and take off the Toolhead Top Cover.
(2) Check whether there are visible screw marks on the capacitor surface or if the capacitor has been pierced.
If you find this issue, please contact Snapmaker support.
¶ Step 2. Check whether the Hub Adapter Board power supply is abnormal
If the capacitor is not damaged, refer to U1 Video Guide: How to Remove the Side Panels to remove the Top Panel and perform cable checks:
Check the following cable connections:
- The 16-pin cable connecting the Main Control Board to the Hub Adapter Board (① in the image)
- The red and black 4-pin cable connecting the AC Board to the Hub Adapter Board (② in the image)
Make sure the cables are fully inserted. With the machine powered off, re-plug the cables once and check whether any connector pins are bent.
If you have a multimeter and know how to use it, you can measure the voltage:
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If the 4-pin connector does not have 24 V but the screen is on, refer to the U1 Power Supply Replacement Guide to remove the power supply cover and check whether the power cables are loose or not properly connected.
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If the 4-pin connector has 24 V but the capacitor pins do not, focus on checking whether the 16-pin cable is properly connected. This cable carries the control signal for powering on the Hub Adapter Board.
¶
¶ Scenario 2: All four toolhead indicator lights are on
¶ Step 1. Check the 16-pin connector on the Hub Adapter Board
Confirm that the 16-pin connector is fully inserted and not tilted or partially seated.
¶ Step 2. Check the 16-pin connector on the Main Control Board
Remove the side panel, then check whether the 16-pin connector on the Main Control Board is obviously tilted.
¶
If the connector is not fully seated:
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Unplug the connector.
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Remove the outer adhesive clip on the cable.
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Reinsert the connector firmly.
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If necessary, apply a small amount of glue to secure it after insertion.
¶ Step 3. Check the USB cable on the Main Control Board
Confirm that the USB cable connected to the Main Control Board is securely plugged in.
If the issue still cannot be identified after completing these checks, please organize the results of each step above and export the machine logs before contacting after-sales technical support.
¶ ✅ Verification
- After restarting, the machine can enter the main menu normally.
- The screen no longer displays the “No toolhead detected” error.
¶ 📚 Related Resources
- U1 Video Guide: How to Remove the Side Panels
- U1 Power Supply Replacement Guide
- How to Export U1 Logs
¶ 💬 Reach out to Snapmaker Support
After following the troubleshooting steps, if you find it difficult to resolve your issue, kindly submit a support ticket through https://snapmaker.formcrafts.com/u1-troubleshooting-request and share your troubleshooting results with some pictures/videos.
Our dedicated support team will be more than willing to assist you in resolving the issue.