6 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
Costly or dangerous
A1 Mini nozzle clogs repeatedly at the black cooling zone; filament cannot be removed even when hot
An owner reports the A1 Mini's nozzles clog regularly at the black cooling section, making it impossible to push filament through even with a hot nozzle, and the extruder starts clicking. The owner tried different filament brands and raised temperature to 240°C without success; a new Bambu nozzle works temporarily then clogs again.
What to check. Expect recurring nozzle clogging on the A1 Mini that may require frequent nozzle replacement. Budget for replacement nozzles and hotend cleaning; the clogging recurs even with fresh Bambu nozzles after a period of use.
A1 Mini and P1S suddenly fail together: poor adhesion, clogged nozzle, spaghetti, filament slipping
A German owner reports both an A1 Mini and a P1S suddenly stopped producing good prints after about half a year: filament barely adheres, the nozzle clogs, prints become spaghetti, and filament slips through. Even after disassembly, cleaning, cold pulls, and new hotends, the A1 Mini scrapes too close over the plate.
What to check. The A1 Mini can develop combined extrusion and first-layer failures that resist cleaning and new hotends. The owner's fixes (disassembly, cold pull, new hotends) did not resolve the scraping-over-plate problem.
A1 series extruder accumulates filament debris and dust, causing gear jamming or stall
Bambu Lab's official Chinese wiki states that after long use, the A1 series extruder assembly can retain filament debris and dust, causing the extruder gear to jam or stop turning; the guide provides disassembly and deep-cleaning steps.
What to check. The extruder gear can jam from accumulated debris over time. Bambu Lab's own maintenance guide requires disassembling the extruder front cover and idler assembly to clean it, which is a non-trivial repair for an owner.
Accelerometer data error on A1 mini linked to toolhead board firmware upgrade failure
Bambu Lab's official error documentation states the A1 mini's HMS_0300-0F00-0001-0001 error (abnormal accelerometer data) can be caused by a toolhead board firmware that was not successfully upgraded, alongside high CPU load or a broken toolhead-to-MC-board connection.
What to check. If the A1 mini shows the accelerometer data error, a failed TH board firmware upgrade may be the cause. The official fix includes restarting, re-seating the USB-C cable between toolhead and mainboard, and re-running the firmware update.
Firmware upgrade on A1/A1 mini fails due to TH board mismatch, network, or SD card issues
Bambu Lab's official wiki documents that firmware upgrades on the A1/A1 mini fail from TH board hardware version mismatch, network/cloud connection problems, insufficient SD card space, cross-version upgrade incompatibility, unplugged TH signal cable, or mainboard/TH board hardware failure.
What to check. Firmware updates can fail and leave the printer in a bad state. Before updating, ensure the TH board is compatible, SD card has space, and the network is stable; if an upgrade fails after replacing the TH board, the hardware version may be incompatible with the firmware.
A1 series nozzle clumping detection error: nozzle wrapped in filament or build plate placed incorrectly
Bambu Lab's official wiki documents the HMS_0300-1A00-0002-0001 error on the A1 mini: the nozzle is wrapped in filament or the build plate is placed incorrectly, detected via the extrusion force sensor (eddy current sensor coil).
What to check. The A1 mini can halt prints when filament accumulates on the nozzle and triggers the clumping detection. The official fix is to clean the material off the nozzle and check build plate placement.
These reports come from the pages linked under each item: owner forums, repair guides and workshops. They are not a diagnosis of any one unit, and a careful check of the one you are buying still applies.
Text from the Kriko 3D printers catalog, version 0.1.1, under the CC-BY-SA-4.0 license.
