Print fan Err... What else to check?  

Re: Print fan Err... What else to check?

Ok, from the assembly instructions it looks like the wires to the fan itself are fixed, so I probably need to check the plug on the control board end...

Re: Print fan Err... What else to check?

Pat, there are plenty of posts concerning wiring different components that you can find in the build manual.
Log into the Prusa website https://shop.prusa3d.com . I know you purchased it pre-built, but you'll have to review the instructions for how it was put together.
Above the pictures select the following:

Support tab
under HELP select Assembly instructions
Categories select your language
For English the next step is select your printer type. The first option "top left" for me is 01 Original Prusa i3 MK3 kit assembly v3.03.
From the "How to Guides" go to chaper 5 "E-axis assembly". Search for your fan information there and the electronic wiring connections under 8 "Electronics assembly".

These chapters will show you how each part of the printer was built. This will get you started until someone else chimes in. There have been issues of wire chaffing in areas so you may want to check the entire run for breaks.

Re: Print fan Err... What else to check?

I opened the RAMBo box and re-seated the fan connector (and the rest). That seems to have fixed it...

thanks,
Pat

Re: Print fan Err... What else to check?

I spoke too soon. This evening I got the print fan error again. I spun the fan to make sure it was not jammed and hit resume. Strangely, this time the machine said "heating" but wasn't actually heating... I could see the nozzle temp dropping rather than increasing. I power cycled the machine, ran the print again from the start and encountered the same print fan error.

Is it possible that I have a bad RAMBo board? Something else I could try?

thanks

Re: Print fan Err... What else to check?

Running with the fan check turned off I have so far not noticed any print issues... but seems less than ideal 😉 The self test always passes. Are there additional diagnostics I could perform to determine if I have a bad fan or board?

Re: Print fan Err... What else to check?

The fan is fully dead now. Hoping to hear back from Prusa.

Re: Print fan Err... What else to check?

Since I'm dead in the water here at the moment I tried a few things with my multi-tester: I peeled back the sticker on the fan exposing the contacts and tested the continuity: the wires seem fine all the way to the plug. I tried measuring the resistance across the fan motor (red-black) but it shows as infinite... I tried a another fan and it gave me a reading... So I am guessing that the motor has died.

Re: Print fan Err... What else to check?

The symptoms of your fan first indicate that the signal cable to the fan has been damaged.
Now that the fan is not working at all, probably more cables have been damaged.

The cables have either been squeezed or they have been bend off due to incorrect cable wiring.
So check the cable wiring so that no more cables can be damaged.

Re: Print fan Err... What else to check?

Same problem here!

On my MK3 (a very early model) the print fan wiring was solid-core, and broke about half way between the extruder and electronics box.

I unwrapped the entire extruder cable assembly and spliced in (3) stranded wires between the fan and electronics box (I soldered the stranded wires directly to the contacts on the print fan).

In my opinion (not worth much), using solid-core wire in an assembly that moves is a VERY poor choice. I hope that Prusa changes the wiring to stranded-core (maybe they already have?).

I have not had any fan errors/problems in hundreds of hours of printing since changing out the wiring...

Re: Print fan Err... What else to check?

Ok so I'm having the same fan problem. Rather then wait forever for a new fan from Prusa does anyone where to source one new, preferably Amazon.

Re: Print fan Err... What else to check?

Hi
I have a problem with print fan also,works ok on self test but fails when printing.I was informed by support to perform factory reset,re-flash firmware and re-calibrate, I have done this twice to no avail only had printer acouple of weeks been working fine until now. Email support again but no reply any help would be appreciated

Regards
Les

Re: Print fan Err... What else to check?

My issue turned out to be pinched wires (on my pre-assembled MK3) a couple of inches from the fan, where they are routed through the extruder case to the bundle. This was causing intermittent problems when printing that didn't show up during the self test because the different positions during printing were apparently putting different stresses on the wires. Moving / straining the wiring harness myself did not reproduce this so it wasn't obvious.

Prusa ended up sending me a new fan but while waiting for it to arrive I removed the old one, figured this out, cut out the bad section, soldiered it back together, leaving the wire out of the channel. It's a kludge but it has been working since.

Re: Print fan Err... What else to check?

Thanks Pat.n
I have ordered a couple of fans from Prusa, but will remove fan and check out the wires

Les

Re: Print fan Err... What else to check?

Hello all.

My replacement print fan is in the process of failing after only 2 weeks. It now only runs on the left and centre of the bed indicating a broken wire. Correction it now only runs on the left hand side of the bed.

Looks like I will have to temporarily refit the old fan as the only faults with that is the speed sensor does not work (also broken plastic due to over tightening).

Prusa really needs to do something about these fans the fail rate is far too high.

Martin