6 sourced reports, with what to check before you buy. Each one links to the page it was reported on.
An owner reports MAXTEMP E1 printer-halted at 200 °C on an Ender 3 with a new hotend; the reply identifies a shorted/open temp sensor or thermal runaway as the cause.
What to check. A MAXTEMP E1 halt on the Ender 3 usually means the thermistor circuit is faulty (short or open) — verify the thermistor reading and wiring before assuming the board is dead.
Reported on: linustechtips.com
A verified buyer review on the Austrian retailer Alza reports the Ender 3's mainboard probably failed after printing only about 10 models.
What to check. A small share of owners report the stock mainboard dying early (within a handful of prints); this is a low-probability but high-cost failure that is hard to predict before it happens.
Reported on: m.alza.at
On the Ender 3 S1 (STM32F4 SoC), flashing a custom firmware build left the printer stuck on the Creality splash screen; recovery required downgrading to an older Creality build first. This is a variant-specific brick path, not the original Ender 3's 8-bit board.
What to check. On Ender 3 S1/V2-style STM32F4 boards, a failed custom-firmware flash can leave the machine bricked on the splash screen; keep the official firmware image on an SD card to recover before re-flashing.
Reported on: github.com
Polymaker's wiki describes the stock original Ender 3's non-geared Bowden extruder as prone to motor skips (clicking) and under-extrusion because the stepper lacks torque; the plastic extruder also cannot have its tension adjusted.
What to check. Expect extruder clicking and clogs on the stock Ender 3 extruder; a geared or direct-drive extruder upgrade is the standard fix, and print speeds should be kept low (about 40 mm/s with a 0.4 mm nozzle).
Reported on: wiki.polymaker.com
A verified buyer reports the stock plastic extruder lever broke after ~1700 hours of printing, and that the metal replacement lever over-tightened the filament, so the replacement is not a drop-in fix.
What to check. The original Ender 3's plastic extruder lever is a known wear part that cracks over time; if replacing it, the metal lever needs tension adjustment or it will grind the filament.
Reported on: m.alza.at
A verified buyer notes the print bed periodically needs re-calibration because of poor spring quality — a first-layer calibration failure mode the pack tracks.
What to check. Budget for better bed springs or a leveling upgrade; the stock springs let the bed drift out of level, causing first-layer failures that are mistaken for bigger problems.
Reported on: m.alza.at
Kriko reads a listing and tells you which of these apply to that exact product. It runs on your computer, needs no account and is free.
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.
