New hotend fan
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@PRIOR123 said in New hotend fan:
I have just installed a new Noctua fan for my ender 3 using the duet wifi 2. It's all gone pretty smoothly up til now. I have put the plug into FAN1 which goes into a buck converter reducing it down to 12V then to the fan. however, FAN1 is set to come on at 45degree which doesn't seem to be happening.
the important thing is how you wired the negative terminal. if you connected that to the buck converter you can actually damage the duet. the buck converter is not mean to run on pwm.
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this is how you should wire the buck converter
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Thanks Both!, I've currently moved it to the always-on point because I thought it no longer matters because the fans are silent. but I would like to use this properly. Though like Veti has said I have a bad feeling that I have damaged the board. if you can you are able to advise how I can test if I have this that would be a huge help.
But thanks for the links, i thought i was going to need a buck converter per fan the way i was wiring it. This makes it MUCH more efficient!
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If you've verified that the fan is working when connected directly to vin or an always on fan terminal, then you can test it on each fan port by itself sending
M106 P0 H-1 S1to enable fan0 port at full speed. P1 for fan1 port, P2 for fan2 port.There's always the chance that a fan mosfet has been damaged.
Do you see any damage to the tiny chips near the fan port?
https://duet3d.dozuki.com/Wiki/Connector_and_spare_part_numbers#Section_Fan_mosfet
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@Phaedrux Soo this issue has now got a little bigger. I tried M106 P0 H-1 S1 and the 5015 blower worked fine and there weren't any other fans plugged in at the time. I then put one of the new fans in and it wasn't happy at all and the entire board went funny like it was shorting. so I turned all power off, now it doesn't seem to like the fuses, I have changed them a couple of times even though they have NOT blown. it seems that when this 'short' happens I need to wobble/remove and reinstall the fuses and everything is fine again. I now think it could be down to a bad earth point. I have checked the PSU and it's fine. But when I try and test the earth pin on the plug and the chassis of the ender 3 there is no noise on my multimeter. Is there a separate earth point for the duet board? in my head, it would seem unusual to have this but I'm not an electrical/electronic engineer. Any ideas?
Also I did check the mosfets and everything looks fine I will upload a picture in a minute
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That looks like a blown mosfet.
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@Phaedrux oh haha, pardon my ignorance but what does that mean? is it repairable? is it the reason for all my current issues?
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@PRIOR123 said in New hotend fan:
pardon my ignorance but what does that mean?
A MOSFET is an electronically controlled switch. Basically, it's what turns the fan output on and off. Yours has exploded, and the most likely reason is that the voltage was reversed when you connected the fan or buck converter. Note that this is the FAN2 MOSFET, marked TR1. The FAN0 and FAN1 MOSFETs (TR5 and TR9) look okay (but may not be).
is it repairable?
Yes, but you'll need some specialist equipment. See https://duet3d.dozuki.com/Wiki/Connector_and_spare_part_numbers#Section_Fan_mosfet
There are a number of forum members that offer repair services, depending on your location: https://forum.duet3d.com/topic/13875/community-repairsis it the reason for all my current issues?
Related to Duet, most likely (less so other personal issues!). It's possibly failed shorted, or partially shorted. Removing the MOSFET may cure this (though leaves the FAN2 output inoperable), hard to say.
Ian
