Centauri Carbon 2: fan errors 701, 702, 703, 705 or 706

Symptom

The Centauri Carbon 2 reports a faulty fan: 701 (mainboard fan), 702 (hotend heat break fan), 703 (part cooling fan), 705 (auxiliary fan) or 706 (chamber fan).

Likely causes, from most to least likely

1. The fan cable is loose or makes poor contact, at the fan or at the board.
2. Something is slowing the blades, such as filament strings or dust (especially on the print head fans).
3. The fan itself is faulty.
4. The mainboard output is faulty or, for the part cooling fan, the print head communication board.

Checks to tell which one it is

• Note the error number: it tells you which fan it is.
• Heat the nozzle from the screen (50 °C is enough for 702) and see whether the fan spins.
• With the printer off, look for strings or dust between the blades.

Before you start

Before taking anything apart, cleaning or adjusting it, switch the printer off and unplug it, unless a step says otherwise, and do not touch the nozzle, the heater block or the bed until they have cooled down. If in any doubt about electricity, heat or moving parts, stop and ask a professional.

Step-by-step fix

1. Part cooling fan (703)

   Switch off, unplug, remove the print head front cover, clean the blades if something is blocking them and reconnect the fan cable.

   Check: Once switched on, the fan spins normally.

   If that does not fix it: If not, the fan or the print head communication board is faulty. With a multimeter, Elegoo says to measure its connector with the fan at 70 % (24 V, 3.3 V and 2.3 V) to know which to replace; without one, replace both.

2. Heat break fan (702)

   Switch off, unplug and remove the lid. Remove the print head front cover (unplug the part cooling fan) and the extruder housing (four screws, 2.0 mm key), unplug the filament sensor, loosen the hotend screws (2.5 mm key), unplug the heat break fan, take it out and clean its blades.

   Check: Once reconnected, with the nozzle at 50 °C, it spins normally.

   If that does not fix it: If it still does not spin, Elegoo says to replace the heat break fan and the nozzle heating plate.

3. Mainboard fan (701)

   Switch off, unplug, lay the printer on its side and remove the bottom cover (ten screws, 2.0 mm key). Reconnect the mainboard fan cable, plug in and heat the nozzle without touching anything inside: with the cover off and the printer on there is a risk of electric shock.

   Check: The fan spins when the nozzle heats.

   If that does not fix it: If it does not, check without touching whether the mainboard light is on: if it is, replace the fan; if not, the mainboard is faulty.

4. Auxiliary and chamber fans (705 and 706)

   Switch off and unplug. Remove the back cover (16 screws, 2.0 mm key; pass the CANVAS extension cable through the gap) and reconnect the fan adapter cable. Then remove the bottom cover and reconnect its cable on the mainboard.

   Check: The fan spins again.

   If that does not fix it: If not, swap the auxiliary and chamber fan cables on the board and switch the other fan on from the screen: if yours still does not spin, replace the fan; if it spins, the mainboard is faulty.

5. Information for Elegoo support

   If you cannot fix it, write to Elegoo support with the error number, a video of the fan, what you have tried and the serial number from the white label next to the power switch.

   Check: Support tells you which part to replace.

   If that does not fix it: Follow their instructions.

Prevention

• Clean the print head fans from time to time: strings and dust slow them down.
• Do not keep printing with error 702: without the heat break fan, heat creeps up the hotend and the filament jams.
• Before opening covers, switch off and unplug; with the bottom cover off and the printer on, do not touch anything inside.

Still not fixed?

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.

Tell the AI about your case

Printers it applies to

Elegoo Centauri Carbon 2.

Official sources

This guide summarises the official documentation linked here:

• Error Code 701 (Centauri Carbon 2 Combo) · Elegoo
• Error Code 702 (Centauri Carbon 2 Combo) · Elegoo
• Error Code 703 (Centauri Carbon 2 Combo) · Elegoo
• Error Code 705 (Centauri Carbon 2 Combo) · Elegoo
• Error Code 706 (Centauri Carbon 2 Combo) · Elegoo