Stop the failing print and trace what is resisting the feed. Clicking tells you that something needs investigation, but not which component is at fault. Keep motor-current changes and hotend dismantling for a diagnosis supported by the machine’s procedure.
Record when it happens
Note whether clicking starts immediately, after sustained printing or around repeated retractions. Record the filament, profile and any recent hardware change. Photograph grinding marks or debris before cleaning them away.
Use the sound together with the timing and feed marks. Picture two failures: filament will not pass during the first layer, or it feeds normally before stopping later in the print. Those observations give the next inspection a different starting point; they do not identify a failed component by themselves. Prusa’s under-extrusion guide[1] includes a nozzle too close to the bed, dirty or misaligned gears, idler tension and insufficient hotend cooling among its checks. Work from the evidence on your machine rather than treating every click as a nozzle clog.
Check the accessible feed path
Using the printer's prescribed power state, inspect the spool path, guides, tubing and drive gears for tangles, damage or debris. Check idler adjustment against the specific extruder instructions; there is no universal tooth-mark depth or quarter-turn setting for every mechanism.
If a large speed, flow or retraction change preceded the failure, return to a supported material profile first. Prusa’s under-extrusion guide recommends stock profiles matched to the machine, filament type and nozzle size as the starting point. Repeat a small representative print there before changing another variable. If you alter the profile and the idler together, a better print will not tell you which correction mattered.
Investigate the hotend by model
Follow the manufacturer’s obstruction procedure for the fitted hotend and nozzle. Prusa’s cold-pull instructions for the listed MK2.5, MK3 and MK3.5 families[2] distinguish a partial clog, where some filament still extrudes, from a complete blockage that needs another procedure. They also explicitly exclude Nozzle X from that cold-pull method. The machine name alone is therefore insufficient: an aftermarket nozzle can change which cleaning method applies. Take the material, temperature and force from the instructions that match the installed parts.
Prusa's heat-creep guidance[3] explains how unwanted heating above the melt zone can obstruct feeding and describes checks for its supported hardware. Check the hotend cooling fan, ambient conditions and assembly against your own model's procedure. A particular fan-on temperature is not universal.
Leave electrical tuning to a documented procedure
Do not judge motor current by touching a hot motor, or turn a driver potentiometer until clicking disappears. Motor, driver, cooling and measurement conventions must all match the machine's specifications.
Where electrical settings have been altered, restore the documented configuration or use the manufacturer’s service process. Increasing current against an unexplained resistance leaves the original feed problem unresolved.
Reassemble and verify
Use the exact hotend's assembly and torque instructions if a component needs replacement. Check whether that procedure calls for hot tightening and how the components are supported; do not substitute a generic nozzle-to-tube recipe.
After one justified repair, repeat the original test and inspect the extrusion as well as listening for the click. If material delivery still fails, send support the timing, photographs and changes you tried. That record lets them work from the same evidence instead of asking you to start the diagnosis again.
