Self test failure  

Re: Self test failure

the left hotend fan is a vital part of the printer and must be running as soon as the hotend temperature exceeds 50°C.
check the wiring and polarity, check if you've connected it to the correct port. if it still dosen't run: check if it is accidentially blocked (during assembly).
if not: have you got a multimeter at hand ? if so, check whether you can read some resistance between the two pins or not.

Re: Self test failure

Checked polarity, plug position, and installation. OK. I was going to externally power fan through the plug to check if it runs when I had the chance. Resistance measurement sounds like a better idea however. Thank you for the suggestion. Prusa support asked if the fan ran. Is the fan supposed to run during self check? I can't find anything anywhere to answer that.

Re: Self test failure

.... Is the fan supposed to run during self check? ...

as far as I can remember: yes. and you need to acknowledge it with <yes>.

Re: Self test failure

OK. I was never prompted for any response of any kind. I also don't think the fan was running although I didn't specially check. Thanks for the input. As soon as I can I will look into this deeper.

Re: Self test failure

What version of the firmware are you using?

In every version I have run self-check on, one of the first things it does is turn on the fan, and ask you if it is running. You can scroll to a yes or no. Then it does the other fan. Again, you have to answer yes or no. If you are not getting these questions during your self test, then I think you may have a firmware issue, and you may want to re-flash it with the latest.

--ajs

Re: Self test failure

I have done what you have suggested along with a couple of things from Prusa support. First I checked Firmware version. It is 3.0.12 (current). I swapped fan connections and I still get the same error: “Selftest error ! Please check : Left hotend fan? Wiring error” Before swapping the connectors I checked if the fan spins at the beginning of selfcheck. It does for only a few seconds. As far as being prompted for “Fan spinning <yes><no>” that happened only once. When I plugged RIGHT side fan into LEFT side fan connector the right side fan spun briefly then I was prompted ONCE. I tried a total of 10 times ( 3 times before and 6 times after) and could not get it to repeat.

Any ideas??

Re: Self test failure

You are not by chance "double clicking" for the one fan prompt? It is a single click.

Can you post a video?

Re: Self test failure

Without doubt I am not double clicking. I think I may have some intermittent issue. I have managed to get the system to act the way it was intended only once. And that was with the two fans reversed on the Rambo board. No matter the configuration it has only done that once, not before or since.

Re: Self test failure

Some additional data. Out of frustration I tapped the fan with my finger. It completed the self check OK the next time I ran it. Hoping it wasn't a fluke I ran self check again and it failed. So I thought maybe I had tightened the fan mounting screw too tight. I completely removed all 4 screws and let the fan rest on the print bed. Self check failed again. And again. and again.................!! Ugh. The fan runs for less than 1 second then the error message appears.

I would REALLY like to use my new printer. Anyone have any ideas?

Re: Self test failure

I am having a similar problem during self test. I have a completely built printer which I can't use as one of the fans is not working. During Self Test, the Left Hand Fan spins, but the Larger Fan doesn't. I have checked and rechecked the wiring and everything seems ok. I have highlited the problem with Prusa Support, but have not received any response as yet.

Re: Self test failure

Since this sounds like a firmware issues, I would do a factory reset, and reload the firmware and try again.

Re: Self test failure

Hi michael.m53, I'm having the same issue.
Had you fixed it? was a firware re-loading successfull?
thanks

Re: Self test failure

Hi, the same problem for me.
FIRMWARE 3.1.0 Self test fail left side fan.
Fan run only for one second and test fail.
During the print the fan run without problem but self test fail.

Re: Self test failure

Had the same problem. Reversed the wire and it works. Red wire up, black on the bottom. It should be the same orientation as the left end fan

Re: Self test failure

Hi everyone.
I know this thread hasn't been written on for some time but i have my fingers crossed that someone will see this message. I have had a MK2s for about 5 months and its been running great but overnight it went to crap. I couldn't get the XYZ calibration to work and now the self test wont pass the left hand side fan failure.
The hot end will heat up to roughly 70 degrees and the i get a fan error message and it shuts down. Did anyone on this thread manage to resolve the fan issue at all. I have tried everything i can think of but all i have a £600 paperweight at the moment.

Can someone please help

Re: Self test failure

Hi everyone.
I know this thread hasn't been written on for some time but i have my fingers crossed that someone will see this message. I have had a MK2s for about 5 months and its been running great but overnight it went to crap. I couldn't get the XYZ calibration to work and now the self test wont pass the left hand side fan failure.
The hot end will heat up to roughly 70 degrees and the i get a fan error message and it shuts down. Did anyone on this thread manage to resolve the fan issue at all. I have tried everything i can think of but all i have a £600 paperweight at the moment.

Can someone please help

The Mk2 does not monitor the fans. During self test, you are asked whether the fans are working and if you just click the button, that is a "No" and you get the fan fail message. You have to be careful with your button presses during the self-test procedure; it's very easy to double-click by mistake.

Peter