@jay_s_uk thank you.. i think i was to quick last night used:

M303 H1 S240 ; auto tune heater 1, default PWM (100%), 240C target

as I read instructions now i should use "M303 T0 SS40" and move the heater close to the bed which i didnt either...

was wondering why fans werent turned on but i saw tuning message fan off will do the PID again once everything cooled down

@dc42
thanks for your quick response. upon further research the VSR pin takes 0-5V or PWM for the speed input of the fan. so i guess this will work with out9?!

@phaedrux THX.. i should have asked earlier would have saved me couple of hours ...well i followed the unstable wiki and changed the branch and apt update & upgrade now DWC is working again. Didnt even had to flash 3.3 again. BIG THX

@achrn thanks for your detailed reply but as described above the fan starts spinning at M106 S0.4
if it would have started at M106 S0.2 I wouldnt have wondered.

I remember in klipper you could define some sort of starting current to give the fan some sort of "kick"

as you see by my language my knowledge in this area is very limited

Nevertheless even starting with M106 S.04 the lowest i can go afterwards is to M106 S0.3 but i cant start the fan with M106 S0.3

So i guess I will operate in the range of S0.4 - 1.0 which is fine for me. I just wanted to know if i can do something else in the configuration since the only thing i read about the fan PWM is that it should start at 20% (M106 S0.2)

@dc42 said in configuring a PWM 4 wire fan:

According to page 6 of the document you linked to, the fan should work down to 20% PWM or lower. The extract you posted refers to the tacho output signal, not the PWM input signal.
You said it is a 24V fan. Do you definitely have the VOUTLC jumper for that output block set to 24V not 12V?

yes the jumper is set on the left to VIN (24V)

the 20% in that document refers to some info from INTEL so i am not sure if it is ment in general.

so on Q25000 once i go over 40-45% i can go back down to 30% and its still spinning - it stops on 25% then

just FYI on Q500 it takes 85% to start - dont know if that info helps

i mean i will live with it just curious if i could improve someting in the settings

FYI thats the FAN
https://noctua.at/de/nf-a14-industrialppc-24v-3000-q100-ip67-pwm/specification

so i have a duet 3 6hc board a just connected a 24v noctua PWM fan to it.

My problem is the Fan starts first spinning at 45% is this normal or connected to the configuration of the fan?

config is

M950 F2 C"!out6" Q25000
M106 P2 S0.0 H-1

only info i could find on the PWM settings was

https://noctua.at/pub/media/wysiwyg/Noctua_PWM_specifications_white_paper.pdf

which doesnt make much sense to me since the max RPM is 3.000 that would mean by that formula 100 Hz?
or are we talking about 100.000Hz so in config <M950 Q100000>

@dc42 ok thanks..this is what initially thought. And i did a quick test with 2 dupont cables..and nothing happened, which was kinda confusing..so i guess ill try again with proper wiring.

so either the documentation is not clear on this or I am just not understanding it.
But how would I wire a physical reset button to duet 3 MB 6HC RESET_EXT ?
1 Pin is GND 1 is RESET they dont need to be shortened, do they?

so to just let everyone know who lands here with his heater fault problem:

I turned out that my fan duct position might cool the nozzle too much since i took off the silicon sock from the heater block.
On 100% fan speed the heater cant really get past 220C if the nozzle is 1mm away from the bed.

@jay_s_uk thank you.. i think i was to quick last night used:

M303 H1 S240 ; auto tune heater 1, default PWM (100%), 240C target

as I read instructions now i should use "M303 T0 SS40" and move the heater close to the bed which i didnt either...

was wondering why fans werent turned on but i saw tuning message fan off will do the PID again once everything cooled down

@jay_s_uk i think u might be on the right track..as i myself just thought of what else happens on layer 2 :)... so for tuning with M303 i need to turn on the part cooling 100% (which i didnt)??

can the cooling cause this problem?
2nd layer usually print cooling fan starts.
And i had for space issues turned my heat block 180 degree (dragon hotend) so the thermistor is at the backside.

unfortunatly that wasnt it.. the heater fault happend again!

Odly it happens when the 2nd layer starts.

1st layer is 40mms
2nd layer 200mms.

These settings have been working for PLA 200C
can this be a problem on PETG 230C?