Fan not spinning error - Prusa Mini  

RE: Fan not spinning error - Prusa Mini

Are you getting the error because the fan isn't spinning or is it happening even if it isn't spinning?Which of the fans is it? The cooler fan or the hotend fan?

RE: Fan not spinning error - Prusa Mini

Both of the fans spin, but it tells me that they are not or that there is debris in it. There's nothing functionally wrong with them from a visual perspective.

I replaced the enclosed fan with a new one (cooler fan?), but that didn't help. I havent replaced the fan closest to the printer nozzle that looks like a tiny PC fan.

I turned off the sensor to print, but it's an uncomfortable solution.

RE: Fan not spinning error - Prusa Mini

Did you ever find a solution?  I've been having the same problem randomly for a while now and every time I check the wiring it looks fine but the problem goes away.  Now I'm having a new problem that is keeping me from printing entirely, the printer fails the bed leveling and when I run self test it fails there too, either from the x and/or y axes or one of the fans.  I'm taking it apart to see if I can figure it out but if you found a solution I'd love to hear it 

RE:

Things to test:

- if the female pins in the end of the fan connector are actually OK, if they did not retracted so the connection is loose, this is especially irritating when you put new cable into the socket and due to force they start to slide up inside the plastic cover and not go over the pins, and are literally lying on the top of the pins due to gravity - then any vibrations will make them loose contact. This is especially common with DuPont wires :). Another idea is that they are too lose and there is not enough contact between the pins and it needs removal from the connection and slight adjustment with the thin screwdriver to bend them slightly to improve contact.

- check if the fan connector on the baseboard are not damaged or bent too much

- check if you have a proper fan - some fans are actually reporting rotations in different frequencies, for example once per 4 rotations, and as a result if the fan is set to spin to 50% it will generate signal about rotations so infrequently that the base board firmware will think it is rotating too slow to not at all. The easiest way to test it is to set in the menu fan to 100% and see how many rotations it is reporting in the menu and checking it over the internet the fan specs. If this is the case that it reports rotations less frequently than it should then just setting minimal speed higher should solve the problem (in PrusaSlicer you can set it in printer settings in Cooling section). Another option is that fan is reporting rotations too frequently, for example every rotation but base board firmware expects it only once per two rotations - in that case signal is too frequent and printer fails to count them and as a result it may think the fan is failing. In that case setting fan speed to 100% will surely report it is failing and only drastic speed reduction help, but as a result it may be not spinning fast enough to provide proper cooling. All in all - if the fan reports RPM too frequently or not frequently enough then it is just better to replace fan with correct one.

If above are okay then you can start thinking about interference around the cables (for example if any other cables, especially power cables are not close to the other signal cables that go out of the printer) or bad baseboard.

RE: Fan not spinning error - Prusa Mini

I was able to solve this by completely disassembling the x-carriage and I think the problem was that there were little wispy strands of TPU wrapped up in the fan or there may have been some stress on the wires but either way it is printing flawlessly again.  Thank you for responding!