Just finished 3.5 upgrade, it won't pass the fan test  

RE: Just finished 3.5 upgrade, it won't pass the fan test

Finished mine yesterday with the exact same issue as you. I haven't tried any troubleshooting yet other than pulling out a new fan I had in my parts bin. I don't want to take that stupid wire bundle apart again if I can help it, so I'll try to take the current fan apart first and clean it. It's pretty dusty, so maybe that's affecting the low speed rpms and throwing the error?

I did ignore the error so I could run a test print though. Woohee, this thing is fast! MK3+ print time was 56 minutes. MK3.5 is 30 minutes. 😀 

I'll post any results of my troubleshooting.

RE: Just finished 3.5 upgrade, it won't pass the fan test

Thanks!   I'm glad it isn't just me.  When you plugged in the old fan, could you get past the fan error?

How did you proceed?  I got the error, but it won't let me run a hotend test (for safety reasons), consequently, I also can't run a first layer calibration.  

I'm with you on the not wanting to unwrap the wires .  It is necessary, but boy is it a pain.

Please let me know what you find.  I will do the same.

RE: Just finished 3.5 upgrade, it won't pass the fan test

The old fan was working fine before disassembly and it spins during the fan test as well, it just throws an rpm error. But it is dirty, so I'm wondering if that is limiting rpm in some way. I got the new fan out but didn't have time to plug it in to the printer. 

You can still run the first layer calibration. Just ignore the warnings about not passing the tests. My printer was working fine Saturday evening, so I had no issue ignoring the failed fan test error last night.

RE: Just finished 3.5 upgrade, it won't pass the fan test

Ok, so my problem appears to be with the print fan even though the error comes right after the question asking if the hotend fan is spinning.

1. I opened the electronics box and reset the plug for the hotend fan. Ran the fan test. Still error.

2. I took my new hotend fan and plugged it into the box. (I just let it hang off the side). Ran the fan test. Still error.

3. I took a new print fan out of my parts bin and plugged it into box. Ran the fan test. Success!

After hearing the fans run during the test I can hear that my installed print fan is noisy compared to the new one. However, when my printer was still in its MK3S+ configuration it never complained about the fans.

All my tests now passed. Now I just need to get motivated to dig back into that wire bundle to replace the print fan. I wish there was something more user friendly than that woven sleeve...

RE: Just finished 3.5 upgrade, it won't pass the fan test

Great troubleshooting!  I will verify your findings sometime today.  I can't believe that we both have bad fans that failed just when we upgraded.  If I can verify your findings, I will put in a bug report.  Hopefully I have spare fans.  Thanks for your help.

RE: Just finished 3.5 upgrade, it won't pass the fan test

So, you'll find this interesting.  I also found old print and hotend fans in my spare parts bin.  Assuming I had the same issue as you, I pugged in the spare printer fan and let it just sit next to the printer.  Failed, same error.  I then switched the hotend fan. Passed!

I then unplugged the spare fan and hooked the old one back up.  I did not rerun the fan test.  However, I've printed several jobs since then.  The old fan spins fine and the prints have turned out as expected.  I think I can skip the re-wrap dillema . I'll let you know if I experience anything else.

RE: Just finished 3.5 upgrade, it won't pass the fan test

I like that idea. Yeah, I’ll stick with my fan till it dies.

 Thanks for the update!

RE: Just finished 3.5 upgrade, it won't pass the fan test

Anyone else been able to trick this to work? I swapped plugs onto a brand new hotend and part cooling fan and the system still failed the test. I am able to use the printer remotely via connect so this has become a big bummer with doing the upgrade.. 🙁

RE:

I had the same problem with failing the fan test with the print fan. I bought a new fan (off Amazon) and passed the test on the first try.

I personally don't think there is anything wrong with the old fan, but I suspect the test is pushing the fan to the limit before giving it a passing grade.

RE: Just finished 3.5 upgrade, it won't pass the fan test

I pulled 2 brand new fans from my spare parts bin and connected them to make the fan test pass, then continued using my original fans.

RE: Just finished 3.5 upgrade, it won't pass the fan test

I just finished my 3.5 upgrade and was able to get through the setup wizard, calibration, and a few prints (benchy, x-axis motor cable support) before running into print fan rpm errors on a print with a longer per-layer time.  The fan test now fails intermittently but I can coax it into passing by spinning the fan fast with compressed air before running the test.  I've ordered a replacement (from Amazon, because shipping) and I'll see how that goes.  Like others, I had no problem with the print fan prior to the upgrade.  It looks like the xBuddy board is more fussy than the RAMBo.

RE: Just finished 3.5 upgrade, it won't pass the fan test

The fan Speed is not high enough and likely makes noise at start up.

Anyway remove the fan so you can get to the back of it. There is a sticker at the back. Only peel off half of it and put a small drop of Oil on the the shaft by the clip.

Then put the sticker back on. I have done this when my 3.5 upgrade failed. Found this  during 3S+ fan noise problems. Replaced it and then evaluated it.

The drop should last 3-9 mths.