Hello everyone,

I’d like to share my experience with a failure I encountered on my Prusa Core One, which I purchased pre-assembled by Prusa (with a €300 surcharge for a ready-to-use machine, as I use it professionally).

After only about thirty hours of printing (roughly three spools of filament), I experienced a critical failure:

The hotend temperature sensor started displaying a constant 248 °C, even though the nozzle was actually cold (measured at 27 °C).

In the middle of a print, the machine then shut off the hotend heating for safety reasons (due to the inconsistent temperature reading).

Since I wasn’t present at the time, the filament became stuck in the hotend.

As the printer continued its movements, filament particles fell into the extruder, damaging the delicate connections of the force sensor (load cell).

Summary:

Hotend temperature sensor failed

Damaged load cell

Clogged nozzle that needs replacement

Full disassembly, cleaning, lubrication, and recalibration required

In order not to halt my work, I immediately ordered a new hotend temperature sensor, the LoveBoard, the load cell module, and some additional spare parts. I performed the diagnosis myself, drawing on my experience with a MK3S (kit version, which has never had any issues over the years) and my background in electrical, electronic, and electromechanical engineering.

I am quite surprised to encounter such a failure so soon on a brand new, factory-assembled Prusa machine that is supposed to offer maximum reliability. I have contacted support to request warranty coverage and reimbursement for the parts I ordered.

Questions for the community:

Has anyone else experienced this kind of early failure (hotend sensor/load cell/LoveBoard)?

Are there any specific points to watch out for on the Core One regarding wiring or sensor protection?

Do you have any advice to prevent this kind of situation in the future?

Thank you in advance for your feedback and shared experiences.

Arnaud