HMS Error Code Reference (Overview)
The A1 reports problems through HMS (Health Management System). Each message has a code and a short description on the screen and in Bambu Handy; tapping it opens the matching Bambu Lab Wiki page.
Most common messages
| Area | Typical cause | First thing to try |
|---|---|---|
| Filament runout / feeding | Empty spool, tangled spool, blunt filament end | Recut the end at an angle, check the spool unrolls freely |
| AMS lite slot cannot feed | Filament stuck in the hub or PTFE tube | Pull the filament back out, recut, reload |
| Nozzle temperature abnormal | Loose hotend connector after a nozzle swap | Reseat the quick-swap hotend until it clicks |
| Heatbed temperature abnormal | Cable or connector issue | Power off and inspect the bed cable (see below) |
| Homing / leveling failed | Dirty nozzle tip, debris on the plate | Clean the nozzle and the build plate, retry |
Heatbed cable notice
Bambu Lab ran a recall for some early A1 units because of a heatbed cable that could wear. If your A1 is from 2024 or earlier and you never received a replacement cable, check your serial number on Bambu Lab's support site.
Safety: Never ignore a repeated temperature error. Turn the printer off and inspect the wiring before printing again.