Hello everyone,
I recently purchased a brand-new Bambu printer with the AMS Lite. The setup was completed successfully, and the printer powers on and functions correctly. However, I haven’t been able to perform any prints yet, as I encountered a technical issue during the filament pre-loading stage.
The issue occurs specifically with Slot 3 of the AMS Lite, which is not functioning properly. When I insert filament into Slot 3:
- The LED indicator does not light up
- The filament is not detected or pulled in automatically
- The pre-loading process does not initiate
Interestingly, I can manually insert and pull the filament through Slot 3 without any resistance — it feeds smoothly as if there is no mechanical blockage, but the slot remains unresponsive.
All other slots (1, 2, and 4) are functioning perfectly and detect the filament as expected.
Here is what I have tried so far:
- Updated firmware on both the printer and AMS Lite
- Restarted the printer and AMS multiple times
- Swapped cables between slots
- Tested different types and brands of filament
- Attempted manual insertion
Since this is a brand-new machine that has never printed, I decided not to proceed with any test prints until this issue is resolved.
Has anyone experienced a similar problem with an AMS Lite slot not recognizing filament, despite no apparent mechanical obstruction?
Any help or technical suggestions would be greatly appreciated before I contact support for a possible replacement.
Thanks in advance!
One more data point:
Unload all filament
Power off the A1
Power on the A1
The lights on the AMS should be blinking in a cycling fashion from 1-4.
What is your #3 doing? Lights or no light?
If no light, and If you want to try to resolve it yourself, I would unscrew that housing, and check to see if the #3 wire harness didn’t get knocked loose during shipping or something.
However, being brand new, you’re well within expectations to ask bambu for a replacement.
Good luck!
Edit: You mentioned: “I decided not to proceed with any test prints until this issue is resolved.” I would not worry about this, but obviously dont use #3. The A1 works without an AMS at all, it is a plug and play accessory.
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Thanks for the response! I followed your instructions.
I completely unloaded all filaments, turned off the A1, then powered it back on. As expected, the AMS Lite LEDs began blinking in a cycle from Slot 1 to Slot 4, in order, and then repeated the loop. I repeated this process several times, including switching the plug-and-play connectors between slots, and the behavior was consistent.
Interestingly, this blinking cycle happens the same way whether or not there is filament in Slot 3. In contrast, when I insert filament into Slots 1, 2, or 4, the blinking stops and only the LED of the active slot stays on.
Additionally, I noticed a mechanical difference:
- In Slots 1, 2, and 4, when I try to manually pull or push the filament, I feel a mechanical resistance, as if the system is engaged.
- In Slot 3, I can freely insert or pull the filament without any resistance — it feels like the motor or gear is not engaging at all.
So even though the LED of Slot 3 participates in the blinking loop at startup, it behaves differently once filament is involved — both electrically (no detection, no LED activation) and mechanically (no resistance).
I suspect a hardware fault in Slot 3 (sensor or stepper not responding). Any insights?
Maybe ask for a replacement part?
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