PWM Fan 1 Output not working

micaheli

Back in late July, I bought a Duet Wifi from filastruder. Only in the last couple weeks have I had time to finalize my FT-6 build and install the Duet. Everything seems to function - great in fact - except for one of the PWM fan outputs. I'm using the duet wiring kit/official connectors and I'm no slouch to crimping, but if I move the working fan from PWM Fan 0 or 2 to PWM Fan 1, the fan ceases to work and no matter what GCode I throw at it, it doesn't seem to want to spin up. I have seen it twitch a little and one time it spun SUPER slow, but that's the extent of it. Acts like a FET is working at half power or something.

I did see this: https://duet3d.dozuki.com/Wiki/Connecting_and_configuring_fans#G-code_controlled_fans and disabling thermostatic control didn't seem to do anything.

Is there something else I can try? Or does this board need to be replaced? I would really love that 3rd PWM fan port.

--Micah Morton

T3P3Tony

@micaheli sounds like a fan mosfet issue but to be sure please post your config.g.I assume you have all three fans setup the same way?

micaheli

In can post my config.g, but it doesn't have that one configured at the moment, but I can tell you I've tried:

M107 P1 ; just to make sure it's off
M106 P1 H-1 ; to disable thermostatic control (read that in that url I posted above)
M106 P1 S255

None of those things made it turn on where it did work on the other two ports.

--Micah

micaheli

config.g

There's my config.g file

micaheli

@T3P3Tony Any thoughts on what my next steps are?

micaheli

I'm really at a loss here. I want to use that output and I was really banking on it working. Does anybody have anything else I can try? Is there a way to test for a bad mosfet? @T3P3Tony ? Filastruder needs an admin here to confirm this to get a replacement sent out.

--Micah

droftarts

@micaheli As @T3P3Tony said, it sounds like a mosfet failure on the fan. If you want to test it, this thread has a good guide for testing the fan mosfet: https://forum.duet3d.com/topic/10027/duet-2-wifi-fan-pwm-0-shorted-dead-fuse-not-blown (thanks @frank26080115 ). You should only attempt to replace the mosfet yourself if you have the necessary skills and experience, because there is a risk that you may damage the PCB or other components, which would void the warranty.

If you would rather a warranty replacement, or guidance about what work you can undertake yourself without invalidating the warranty, contact Filastruder and reference this forum thread. @T3P3Tony and @dc42 have agreed to a warranty replacement.

Ian

pipersw

@micaheli Have you unplug the fan with board powered ? Have you reverse the polarity of fan ?
If you have done one of these step you have blown a mosfet

micaheli

I have tried inverting the output to the fan through the gcode. I verified the fan's functionality and polarity on another PWM output as well as the always on outputs.

As for unplugging with the board powered, I did not do this as I typically don't work on electronics while they are powered. I've learned the hard way when I was young.

elmoret

@droftarts said in PWM Fan 1 Output not working:

@T3P3Tony and @dc42 have agreed to a warranty replacement.

Where did they do this? I do not see such confirmation in this thread.

micaheli

@droftarts Thanks for that! As I mentioned, I'd prefer a warranty replacement for sure. I think @T3P3Tony and @dc42 have to comment on this thread directly for filastruder to honor it.

I have the skills to replace a mosfet, but not the equipment at this time. I also would hate to void my warranty. That's half the reason I buy genuine stuff in the first place. (the other half being that I'm supporting the creator)

micaheli

Filastruder is sending me a new unit. Thanks everybody for your help. I may make a digikey order for those fets now though, just so I have them when my warranty ends. haha.

droftarts

@elmoret said in PWM Fan 1 Output not working:

@droftarts said in PWM Fan 1 Output not working:

@T3P3Tony and @dc42 have agreed to a warranty replacement.

Where did they do this? I do not see such confirmation in this thread.

I have that power! Mwaaaahhaahahaha....

Ian
(Part-time Duet 3D purveyor of tech support / documentation scribe / firmware test mule - but don't tell everyone!)