Extruder kit bottom fan not spinning

Every time I start a print, my printer complains that the fan is not spinning correctly - and rightly so. It’s not spinning at all. It’s the fan under the extruder. I’ve made sure that the wires on the PCB are still straight and that the plugs are tight, as well as making sure there was nothing lodged in the fan itself. Also turned the printer off and back on - Is there a way to test whether the problem is the PCB or the fan without having to buy anything yet? I don’t want to spend money on buying the wrong part.

Seems like I should be able to use a multimeter and touch it to the pegs where the fan plugs in or something but I don’t know how anything about that.

@sovol3d

Put in a ticket at info@sovold3d.com

Exchange the 2 fan plugs on the toolhead bord. Which fan spins now?

Be sure to try a OTH reflash before scrapping the toolhead board.

Thanks! What’s an OTH reflash?

I don’t have an Ace but my understanding is that under the “update firmware” menu there is a way to force a reflash of the firmware even if it is already up to date.

Very very rare but there is a 0.0001% chance the toolhead MCU has experienced a “bit flip” and is expecting to see the fan on another pin.

Factory reset is going on now but when it said “Exception in Fan” I thought “Fine, I’ll move the plug over” and put it in another, similar sized port. BOOM! Fan immediately started spinning. Either I put it in the wrong port when putting things back together after taking it apart for a clog removal, or I had it in the right port and this is another port. I think it’s more likely that I put it back together wrong. This must be the 3D printing version of a PEBCAK error.

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There are in fact 3 fan ports on the tool head board.


It appears fan3 is the part fan (large lower) and fan2 is the extruder (small on the side)

Klipper can’t tell the difference but you’re headed for another clog if they are backwards. Extruder will overheat and cause the filament to be too soft at the drive wheels.

Just double-checked and it’s in the right port now. I had it in Fan1 when it wasn’t working.

Thanks for your patience and helpfulness.