Prusa 3D printer troubleshooting
11 guides to fix Prusa 3D printers: the symptom, the likely causes, how to check which one is yours and the step-by-step fix, with official sources from Prusa Research.
Printers covered: CORE One, MK4, MK4S, MK3S+, XL, MINI+, SL1S SPEED and XL+.
Each guide summarises the official documentation and says whether usi3d has already verified it on a machine.
Adhesion and first layer (3 guides)
- First layer too high, too squished or uneven on MK4, MK4S or CORE One (load cell)
On an MK4, MK4S or CORE One, which calibrate the first layer by themselves with the load cell in the print head, the first layer comes out too high (round lines with…
- MINI+: wrong first layer height, Live Adjust Z at its limit or Z rises while leveling (SuperPINDA)
On the MINI+ the first layer is too high or too squished, Live Adjust Z reaches -2.000 and the nozzle is still too far away, or during homing or mesh bed leveling the Z…
- MK3S+: wrong first layer height, nozzle hits the bed or bed leveling fails (SuperPINDA)
On the MK3S+ the first layer is too high or too squished, the nozzle scrapes or crashes into the sheet, XYZ calibration fails, or you see «Bed leveling failed.
Extrusion (3 guides)
- Multi-tool XL: a tool is not picked up or parked properly (dock and toolchanger)
The XL fails to pick up or drop off a tool at its dock, a tool bumps into a parked one, or a toolchanger error appears, such as «Toolchanger problem» (#17813), which…
- Multi-tool XL: colours do not line up or tool offset calibration fails
On an XL with several tools, what each head prints is shifted relative to the rest, or the offset calibration fails with «Tool offset out of bounds» (#17104) or with «XY…
- The MMU3 does not load, does not unload or the filament gets stuck
The MMU3 stops at a colour change and the printer shows an error, for example «FINDA didn't trigger» (#04101), «FINDA: Filament stuck» (#04102), «Filament sensor didn't…
Connectivity and firmware (1 guide)
- MK3S+: the IR filament sensor fails (asks for filament change, no autoload or no run-out detection)
On the MK3S+ autoload does not start when you insert filament, the printer does not pause when the filament runs out, or at the start of every print it asks you to…
Resin (1 guide)
- SL1S SPEED: the print does not stick to the platform and stays on the film
When the platform rises there is nothing attached; when you take out the tank there is a layer or blob of cured resin stuck to the FEP film.
Error codes and messages (3 guides)
- Load cell errors on MK4, MK4S and CORE One
The screen shows a load cell error (the print-head sensor that detects when the nozzle touches the sheet) and the printer does not continue.
- My Prusa shows an error with a five-digit code and a QR code
The Prusa printer shows an error screen with the name of the problem, a short description, a QR code, a link and a five-digit number preceded by #, for example #13202.
- The Nextruder filament sensor does not detect filament properly (MK4, MK4S, CORE One)
The printer says there is no filament when there is, or the other way round; it pauses the print for no reason, will not let you load, the sensor calibration fails in…
Products that may help
Products from the usi3d shop that fit these guides, chosen for the fit and not for the commission. Check that they work with your printer before buying.
Symptoms in the Prusa guides
- The printer shows an error code or message
- Does not stick to the bed
- Uneven first layer (thin and thick areas)
- The multi-material system fails (does not load, cut or jams)
- Clogged nozzle or hotend
- Unlevel or warped bed
- Homing or a sensor fails (endstop, levelling)
- Problems after a firmware update
- The resin print does not stick to the build plate
- The print sticks to the vat film (FEP)
Other brands
Can't find your case?
Tell usi3d's AI about your case: choose your printer, describe what you see and add photos if you like. It proposes checks step by step, with their sources.