Hotend fan continuously fails self-test
Anyone else having problems? The fan is clearly spinning freely (on its own power) when I start the self test. I'm positive it's installed correctly and I've taken it apart 3 times to reinspect everything to confirm. Nothing is pinched.
It continues to fail on the self test.
In case this is relevant, I did just have to replace my LCD board as the original board had bent USB pins. I doubt this has anything to do with the fan; however, I wasn't failing self tests before I changed LCD boards.
Any thoughts?
RE: Hotend fan continuously fails self-test
Can you see RPM of the fan on the LCD?
When you changed the LCD, did you touch anything inside the xBuddy box?
RE: Hotend fan continuously fails self-test
Can you see RPM of the fan on the LCD?
When you changed the LCD, did you touch anything inside the xBuddy box?
I did not touch the xBuddy.
Very curiously, right after I posted this I went and did another fan check (that failed). Then I tapped the fan lightly as it was spinning up for another test and.... it passed. Then it passed a couple more times after that. Finally another self-test later and still passing. Did I fix it by just hitting it? Was violence the answer?
I have no scientific reasoning as to why, but after the light tap while the fan was running, my fan failures appear to have ended.
RE: Hotend fan continuously fails self-test
The fan must have a faulty tachometer or a break in the wire or connector. You might want to contact Prusa support or proactively order a replacement to avoid future downtime.
RE: Hotend fan continuously fails self-test
I have same problem.
RE: Hotend fan continuously fails self-test
I also ran into this, after upgrading my printer to MK4.
From observation, pass threshold for the hotend fan test seems to be 7000 RPM. My fan does get to that speed, but it takes a little longer than the test permits. I think perhaps the test parameters should be changed to allow a little more time for the fan to spool up.
Anyway... I found that if I loosened the fan from the heatsink a little, it would spin up a little faster / actually pass the test
RE: Hotend fan continuously fails self-test
Just unpacked my assembled MK4, turned it on for the first time to start calibration and fan test failed. Can I ignore it or do I need to contact support already?
RE: Hotend fan continuously fails self-test
I Hello, I also had problems with the hotend fan in the self-test.I then unscrewed the fan and did the test, or held the fan by hand and then it worked.I then screwed the fan back on, but not as tight as before. After that I had no more problems.I suspect that I screwed the fan on a little too tightly at first.
RE: Hotend fan continuously fails self-test
I just upgraded two MK3S printers to MK4. The second printer failed the self test for the fan just as described. And I did exactly the same thing and it fixed it.
I Hello, I also had problems with the hotend fan in the self-test.I then unscrewed the fan and did the test, or held the fan by hand and then it worked.I then screwed the fan back on, but not as tight as before. After that I had no more problems.I suspect that I screwed the fan on a little too tightly at first.
RE: Hotend fan continuously fails self-test
Yeah, mine also failed on a full kit build, I just unplugged it and plugged it back in - worked fine after that - go figure!
RE: Hotend fan continuously fails self-test
Static pressure, or in other words air resistence has quite an effect on fan max speed. This sounds to me like Prusa underestimated that when setting the required rpm in the self test. That would at least explain why failed tests are successful when unmounting the fan to allow for unobstructed air flow.
Mk3s MMU2s, Voron 0.1, Voron 2.4
RE: Hotend fan continuously fails self-test
I think in my case it was I had to reseat the fan and not tighten things as much as I did. this only happened on the second upgrade. It's been running like a champ since.
Static pressure, or in other words air resistence has quite an effect on fan max speed. This sounds to me like Prusa underestimated that when setting the required rpm in the self test. That would at least explain why failed tests are successful when unmounting the fan to allow for unobstructed air flow.
RE:
In my case, even after detaching the fan, bending it very gently and reattaching it with very light force all did not help!
I also found that the fan was able to reach the 7000 RPM when holding it in my hand but also during the self test. But the measurements stops too early and the test fails every time.
This is probably a software bug or the fans do not meet the requirements.
Everything else worked fine, and I have assembled the printer really carefully.
RE: Hotend fan continuously fails self-test
I was having the same issue I lightly tapped thecenter of the spinning fan as it booted Then it passed self test!
Anyone else having problems? The fan is clearly spinning freely (on its own power) when I start the self test. I'm positive it's installed correctly and I've taken it apart 3 times to reinspect everything to confirm. Nothing is pinched.
It continues to fail on the self test.
In case this is relevant, I did just have to replace my LCD board as the original board had bent USB pins. I doubt this has anything to do with the fan; however, I wasn't failing self tests before I changed LCD boards.
Any thoughts?
RE: Hotend fan continuously fails self-test
Came here from Google. Loosening the screws on the fan worked for me and it has passed the test two times now.
Thank you! 🙂
RE: Hotend fan continuously fails self-test
Two issues. Either the fan is bad (broken wire or bad tachometer) or there is a problem with the Loveboard. Get a known good fan and plug it into the Loveboard and see if that doesn't fix the problem, if it doesn't, the Loveboard has a problem.
Senior Life member of IEEE.
RE:
I have contacted the customer support via chat. They have confirmed that there is a known software bug.
RE: Hotend fan continuously fails self-test
Adding a 3mm plastic washer on both screws between fan and heatsink works well too.
RE: Hotend fan continuously fails self-test
I had the same issue. Updating from firmware 5.0.1 to 5.1.0 fixed it for me.
RE: Hotend fan continuously fails self-test
Loosening from the fan worked for me too