Stop long prints until the heatsink fan is restored; clean the fan, check its connector and voltage, confirm firmware control, and replace a noisy or stalled un.
Start hereStop long prints until the heatsink fan is restored; clean the fan, check its connector and voltage, confirm firmware control, and replace a noisy or stalled unit.
First safe actionRun the first safe check and change one variable at a time.
Proof targetA small representative test no longer shows the original symptom.
Match the failed area to the visual before changing a setting.
Repair progress0 of 8 complete
Step 1 of 8
Allow the hotend to cool and disconnect power.
Keep the problem and target visual open while you make this change.
Why this matters
Filament strands or dust block the blades.
Setting or checkFan threshold
Use the manufacturer default unless an approved configuration requires change.
Expected result
The original symptom no longer appears during a representative calibration or short test print.
Step 2 of 8
Remove visible debris without damaging the blades.
Keep the problem and target visual open while you make this change.
Why this matters
The fan cannot start reliably.
Setting or checkRetraction
Do not increase retraction to compensate for heat creep from a failed fan.
Expected result
Measurements, temperatures, motion, feed, or exposure remain stable through the complete test.
Step 3 of 8
Spin the fan gently and check for roughness or contact.
Keep the problem and target visual open while you make this change.
Why this matters
Toolhead motion interrupts power.
Setting or checkHotend temperature
Keep testing within a normal material range.
Expected result
No new warning, collision, leak, electrical smell, unusual heat, or material damage appears.
Step 4 of 8
Inspect the connector and cable through toolhead movement.
Keep the problem and target visual open while you make this change.
Why this matters
The installed fan does not match the machine.
Setting or checkFan threshold
Use the manufacturer default unless an approved configuration requires change.
Expected result
The successful change is recorded with printer, material, slicer, nozzle or resin, and date.
Step 5 of 8
Confirm the fan voltage, size, airflow direction, and connector match the printer.
Keep the problem and target visual open while you make this change.
Why this matters
The fan may start only above a configured temperature.
Setting or checkRetraction
Do not increase retraction to compensate for heat creep from a failed fan.
Expected result
The original symptom no longer appears during a representative calibration or short test print.
Step 6 of 8
Use printer diagnostics to test the fan output if supported.
Keep the problem and target visual open while you make this change.
Why this matters
Filament strands or dust block the blades.
Setting or checkHotend temperature
Keep testing within a normal material range.
Expected result
Measurements, temperatures, motion, feed, or exposure remain stable through the complete test.
Step 7 of 8
Replace a fan that stalls, grinds, or starts intermittently.
Keep the problem and target visual open while you make this change.
Why this matters
The fan cannot start reliably.
Setting or checkFan threshold
Use the manufacturer default unless an approved configuration requires change.
Expected result
No new warning, collision, leak, electrical smell, unusual heat, or material damage appears.
Step 8 of 8
Verify stable hotend temperature and a long retraction test after repair.
Keep the problem and target visual open while you make this change.
Why this matters
Toolhead motion interrupts power.
Setting or checkRetraction
Do not increase retraction to compensate for heat creep from a failed fan.
Expected result
The successful change is recorded with printer, material, slicer, nozzle or resin, and date.
Controlled test log
Change one variable, then record what happened
This keeps temperature, retraction, speed, mechanical, and material tests from blending together. The history stays private in this browser.
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ExtrusionHeat Creep Jam Fix
