Front/left fans Swapped during self test
I just finished assembling my MK3 and the Selftest is failing on the first step. It spins both fans at the correct time according to the display and then shows the error "Selftest error ! Please check : Front/left fans Swapped". I checked the connections again and they are correct. The correct fan does spin when it is shown on the screen. I did update to the latest firmware, 3.1.1 RC4 B143, before I tried the self test.
Re: Front/left fans Swapped during self test
Same issue for me.
I built the (Mk3) kit, ran the preflight checks – all ok. Calibrated xyz – all good. Calibrated the first layer – all good. Printed the prusa logo – perfect. Upgraded the FW (3.1.1 RC4 B143);
Went to print a project from the SD card (in gcode form), card was recognised, preheated ok, it did the z calibration fine, heated up (PLA) fine, ran through SD: 0-100% on the LCD – but then nothing, just stayed in the bottom left position, and then the LCD said – i3 Mk 3 ready?
I decided to re-calibrate it (as I had moved the printer to its new home, and thought the move might have thrown something out of kilter) – I ran the wizard – the side fan was ok, but I got that same message re fans being swapped for the front fan. I ran it twice again to make sure it wasn’t a glitch but got the same message.
Went into self test – the two fans passed but it said there was an error with the thermistor not being connected?
Re: Front/left fans Swapped during self test
Doesn't sound like the same issue, but very possibly related. I chatted with the company and they said they've had a couple of reports of the problem I experienced and thought it was related to the new firmware. He suggested I just skip the self test and continue on with the xyz calibration. I haven't had time to do that yet so I don't know if I'll see other issues or not. He did say they were working on it.
Re: Front/left fans Swapped during self test
Thanks for letting me (/us) know. My issue whereby it wouldn’t print from the SD card was the prelude to experiencing the same issue (Front/left fans Swapped during self test) as you, be interesting to see when you run the xyz calibration you get the same (or a different??) error message…
It was strange that my xyz calibration threw up the fan error but the subsequent separate/standalone self test passed both fans but threw up the thermistor error message. Sounds a bit buggy to me….
Re: Front/left fans Swapped during self test
Finally had time to continue to the calibration without completing the self test. The first time I tried the calibration it stopped in the middle of the second pass on the four sensors. The only thing on the display was a thermometer in the bottom right corner. I did the test again later and it completed this time, but the display blanked while it was doing the test on the first sensor. When it moved to the other sensors it updated the display to say "2 of 4", etc., but that was the only thing on the display, nothing on the first two lines. Obviously, something happened to the display and it doesn't re-write the entire screen when it goes to the next points.
The calibration did finish. I went to do the first layer calibration and got the "min temp." error warning. I've read through the forums and see this is fairly common. I also read that there is new sensor to eliminate this error in cold environments, but it's not written into the firmware yet. Is that correct? I did get past it with the hair dryer/heat gun trick.
I did get the first layer calibrated and was able to successfully print the PRUSA logo from the SD card.
The bottom line is that I do have the printer up and running now, but this build/test/calibration was not a good experience compared to the MK2 that I built. I'm wondering if growing pains has become a problem at Prusa. Was the MK3 really ready for prime time?
Re: Front/left fans Swapped during self test
I was also getting this error message and I was quite certain that I had connected them correctly, but I tried to swap them anyway, but got the same error message. So I swapped them back and tried again, same problem, then I tried to reset the printer instead of powering off, and after this the calibration went through without any error messages.
Don't know if you have tried this but it is worth a shot.
Re: Front/left fans Swapped during self test
I did try resetting because I think I had seen that elsewhere in the forum, but it didn't help. It still failed in that same spot in the self-test. Thanks.
Re: Front/left fans Swapped during self test
Easy fix. If both fans are working. Left will pass but print fan will ask if it is spinning. Say no. It will ask you again immediately again the same question. Say Yes. Test will pass.
Re: Front/left fans Swapped during self test
Thanks for the solution aron.b2! Setup went great after getting past that initial error.
Re: Front/left fans Swapped during self test
Easy fix. If both fans are working. Left will pass but print fan will ask if it is spinning. Say no. It will ask you again immediately again the same question. Say Yes. Test will pass.
Sounds like a hardware race condition the software doesn't account for. Servicing an IRQ taking 50us and the software only waits .1us (or whatever the cpu clock is). One of the more common risks of open source.
RE: Front/left fans Swapped during self test
Easy fix. If both fans are working. Left will pass but print fan will ask if it is spinning. Say no. It will ask you again immediately again the same question. Say Yes. Test will pass.
For me it said the extruder fan was working but the left/print fan failed. It asked if the "left fan" was working and I said no and then it asked if the "print fan" was working and I said yes and it passed. Thank you for your guidance! You led me to the solution!