"Printing Anomaly" Error Code: 0002 0524 0001 0038 - resolved

U1 Toolchanger
1

Hello,

Snapmaker support helped me to diagnose and resolve this error I’ve been getting for the past week or two. I’m uploading this here incase it helps anyone else down the line having the same issue. I also would encourage you to contact Snapmaker support, as I had very a very good experience with them.

To give some back ground, here is my submitted ticket in it’s entirety:

I’m getting this error:
Printing Anomaly
Error Code: 0002 0524 0001 0038
“Check if the filament for Toolhead 2 is broken inside the tube, tangled on the spool, or if the toolhead is clogged. After troubleshooting, tap to resume printing. If issue persists, contact technical support.”

This happens on 4 different PLA filaments, including SnapSpeed PLA. I’ve checked for each of the possible causes described in the error and I’ve found nothing (not tangled, not broken, not clogged). I’ve ensured I’ve selected the correct filament type of PLA for that toolhead.

I’ve dissasembled the toolhead completely, per the U1 Wiki instructions, down to the extruder gears and sensor. I didn’t see any filament clogs, gunk or pieces on the extruder or the pathways. Still I cleaned the metal extruder gears with 99.9% alcohol and a cotton swab. I removed the sensor and I cleaned it too and it’s pathway. All of the circuit connectors looked fine. No broken wires.

Then I reassembled and ran full calibrations. Then I heated the hotend to 220c and manually extruded a good amount of PLA filament through the nozzle using the touchscreen toolhead#2 control panel. That makes me think there likely is NOT a clog in the hotend nozzle.

I ran a test on toolhead#2 to print a small print model in PLA. It then starts it’s first layer, but after a minute or so, before it gets halfway finished with 1st layer, it gives the same Printing Anomaly error as before.

I’ve ordered a replacement Toolhead assembly from the Snapmaker U1 that I hope will resolve this and hopefully that will arrive to me in a week or two.

I’m unsure though why it is having this error. I’m thinking it may be the extruder motor isn’t producing enough torque? Or maybe I do have a hotend clogged, just barely, where it extrudes fine manually but when tasked to extrude at specific pressures or flow rate it is clogged perhaps enough to trip the error?

I may try swapping hotends on the problem toolhead #2 with another hotend, just to see if that resolves the issue with toolhead #2.

What are your thoughts? Can you give me a diagnosis plan or solution?

thank you

Here was Snapmaker Support reply. In short, they asked me to run a simple test while bypassing the filament feeder and do a manual extrusion test to ensure the toolhead it working okay. Then they asked me to swap filament feeders from side to side:

Ariel (Snapmaker)

Jun 29, 2026, 12:18 GMT+8

Hello,

We sincerely apologize for the inconvenience caused.

To further troubleshoot the issue, please temporarily bypass the filament feeder (that is, do not use the filament feeder during this test) and perform a manual extrusion test.

1. On the printer touchscreen, select the corresponding toolhead and heat the hot end to 250°C.
2. Remove the PTFE tube from the top of the toolhead.
3. Press and hold the orange Extruder Lever on the Extruder Unit.
4. Manually feed the filament into the top of the Extruder Unit while continuously pushing it downward.
5. Observe whether the filament can be extruded smoothly from the nozzle.

You may refer to the following video for the testing procedure. After setting the temperature on the touchscreen, please follow the method shown in the video to verify whether extrusion is normal. Please also check whether the extruded filament forms a smooth cylindrical strand and record a video of the extrusion process for us to analyze further.

https://drive.google.com/file/d/1Rn1-6hruMgU0T0Ms3gEO1eNJJ07qCPdu/view

If you have confirmed that all of the above steps have been completed correctly, but the issue still occurs frequently, we may need to further investigate whether the Filament Runout Sensor is malfunctioning.

In this case, please swap the left and right filament feeders (install the right-side filament feeder labeled 3/4 into the left-side 1/2 position, and install the left-side filament feeder labeled 1/2 into the right-side 3/4 position), then observe whether the issue follows the 3/4 filament feeder.

If the issue moves together with the 3/4 filament feeder, it indicates that the 3/4 filament feeder itself is faulty. Please make sure that the printer is completely powered off before disconnecting or reconnecting any cables.

If the issue does not change after swapping the filament feeders, please inspect the filament feeder cables and make sure they are not loose, damaged, or broken.

Thank you for your cooperation and support. We look forward to your feedback.
Best regards,
Ariel

I followed their diagnosis instructions:

Hello,

Good diagnosis instruction. That was it, the Filament Feeder. After swapping filament feeders, toolhead #2 which originally was having “printing anomaly”, began working and successfully completed a long 4 hour print job. Then I tested toolhead#3 and it began having the “printing anomaly”. The problem followed the filament feeder after swapping it to the other side.

Thank you

Snapmaker is sending me a replacement filament feeder assembly:

Ariel (Snapmaker)

Jul 1, 2026, 12:27 GMT+8

Hello,

Thank you for your support of Snapmaker. Our technical support team will do our best to help resolve your issue.

We are glad that we have identified the root cause of the issue. Based on the troubleshooting results, this issue is caused by the filament feeder.

We will send you a new right-side filament feeder as a replacement.

We will arrange the replacement shipment as soon as possible.

Thank you for working with us during the troubleshooting process. We appreciate your patience and cooperation.

We look forward to your reply.
Best regards,
Ariel

Before I created the ticket I pre-emptively ordered a replacement toolhead assembly. But it wasn’t until after I ordered the part that I thought I should contact their support, just to see what they say. I should’ve contacted them first, but at least now I’ll have extra spare parts.

Anyway, if you are like me and you’d only contact support as a last resort, I encourage you to contact them if you run into these types of issues and cannot resolve on your own. Snapmaker support really is quite helpful.

And so, this is a good report and I’m happy with the outcome.

See ya

2

Thanks for sharing. I’ll also forward this to Ariel so she knows her work is highly appreciated.:grinning_face_with_smiling_eyes:

3

Had the same issue with tool head #1 which worked fine if I didn’t go through the feeder. Took the cover off the feeder & there was excessive grease in it. Cleaned this out with cotton swabs & IPA all has been well since.

4

I’m thankfull for the free replacment part sent in by support, which did fully fix my issue.

But I still wanted to see if I can dissasmble and possibly “fix” the failed filament feeder. I marked my failed filament feeder assembly with a black marker pen, giving it a big X on the housing so I don’t later confuse it with a good feeder. Then I fully dissasembled the failed filament feeder. I’m looking for any signs of what caused it to fail. I’m also curious how it is constructed.

The photo below is showing the feeder with the white half cover removed. On the back side of this circuit board, where I indicate with red squares, is a little coil spring and a tiny magnet.

I removed that circuit board and examined the springs and magnets. They seemed fine, springs were aligned correct with the magnets. Not finding an issue, I cleaned with isopropyl alcohol the contact areas on backside of this circuit board where the springs and magnets exist.

I’m hypothesising here, but I think when the filament passes into the tunnel path (those tunnel holes on top in the photo), it pushes in on the magnet and spring. There is probably a proximity sensor on circuit board that can sense when the magnet is pushed in, telling the U1 that filament is in the feeder.

I didnt see any clogs or gunk or anything obvious or broken. I did see globs of white grease on the brass helical gears. Globs of grease on that narrow pinion gear, and also on the main big gear, but also globs of grease around the white plastic shaft area. I cleaned that grease a bit, leaving it on just the gears only.

DSCF0014
DSCF00141920×1440 1000 KB

I’ll try testing this reassembled feeder to see if this magically fixes it. I don’t have high hopes because I didn’t change anything, just cleaned it a little.

The feeder assembly is quite interesting and a nice design. It was interesting to see how it is built. I’m not showing it all dissassembled in the photo, but I took it completely apart and then reassembled. Pretty straight forward and not difficult, and it’s nice to know how to dissassmble/reassemble our machines..

I’ll update later this weekend after I test the cleaned filament feeder.

5

I tested a 4 hr print model using the previously “broken” filament feeder which I disassembled and cleaned per my previous posting above.

It’s a miracle! It’s working. yeah!