Identifying Issues:

1. Marlin board cooling fan makes abnormal noise, has reduced speed, or does not rotate.

Replacement Method:

1. Lay the M5 machine back. Use an H2.0 hex wrench to remove the 7 bottom cover bolts (marked in green) and an H2.5 hex wrench to loosen the 4 foot pad bolts (marked in red).

2. Open the small cover on the bottom cover. Use an H2.0 hex wrench to remove the TYPE-C wire fixing bolt, then pull out the TYPE-C wire and Z-axis motor wire.

3. Open the bottom cover plate. Pull out the Marlin board cooling fan wire terminal, then use an H2.0 hex wrench to remove the fan fixing bolts.

4. Replace the old fan with a new one. Use the H2.0 hex wrench to secure the new fan and insert the fan wire terminal.
5. Install the bottom cover plate back, passing the TYPE-C wire and Z-axis motor wire through their corresponding holes (pay attention to the direction of the Z-axis motor wire).
6. Use an H2.0 hex wrench to fix the bottom cover bolts and an H2.5 hex wrench to fix the foot pad bolts. Plug in the Z-axis motor wire and TYPE-C wire (ensure the Z-axis motor wire and TYPE-C wire correspond to "R/L").
7. Use an H2.0 hex wrench to lock the TYPE-C wire retainer.
8. Reinstall the bottom cover panel.

If the issues persist after replacement, please contact Ankermake customer support at us for further assistance.