all pwm fan outputs do not work.

invertmast

So i've been connecting my new Duet Wifi to my home brew printer (fresh build and install, the board i've only had for 2 weeks or so) and the last thing I had left to hook up were the Fans. As i have done with all my wiring, i made up the extensions and checked for positive continuity between each connector pin at either end. All of my fan wiring has checked to be Good, but None of the fans work on the PWM outputs of Fan O/1/2.

I have used known fans as I can remove the connectors from the PWM outputs and connect to the always on connectors and the fans instantly begin to work.

My Config.g is as follows:

; Fans
M106 P0 S1 I0 F100 H-1 ; Set fan 0 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P1 S1 I0 F100 H-1 ; Set fan 1 value, PWM signal inversion and frequency. Thermostatic control is turned off
M106 P2 S1 I0 F100 H-1 ; Set fan 2 value, PWM signal inversion and frequency. Thermostatic control is turned off

; Tools
M563 P0 D0 H1 F0 ; Define tool 0
G10 P0 X0 Y0 Z0 ; Set tool 0 axis offsets
G10 P0 R0 S0 ; Set initial tool 0 active and standby temperatures to 0C

Using the M106 P (0/1/2) S1 does not turn the fans on either.

Using the above command, i do have the following output voltages:

Fan 0= 20.9v
Fan 1= 2.7v
Fan 2= 20.9v

Using the Command: M106 P(0/1/2) S0 results in output voltages of:

Fan0= 24.4v
Fan1= 4.3v
Fan2= 24.4v

Prior to connecting the fans to the PWM outputs i hooked each one up individually to one of the always on ports to verify proper wiring and operation. All worked as expected then.

I've searched and googled for a few hours last night and came up batting zero for any sort of remedy to the issue, so hopefully you all will be able to help me get it figured out.

The only thing i have come to the conclusion of is the fan Mosfets are likely blown?

AndreS

Try M106 P0 S1.0 or M106 P0 S255

invertmast

@andres said in all pwm fan outputs do not work.:

Try M106 P0 S1.0 or M106 P0 S255

Doing so changes the fan to 100% via the webconsole but there is no change in fan operation.

dc42

Looks like fans 0 and 2 either have either blown mosfets or the mosfet source terminals are somehow not connected to ground. The fan 1 readings are odd.

Can you post a close up photo of the area of the Duet around the fan connectors, so that I can see the fan mosfets?

invertmast

@dc42 said in all pwm fan outputs do not work.:

Looks like fans 0 and 2 either have either blown mosfets or the mosfet source terminals are somehow not connected to ground. The fan 1 readings are odd.

Can you post a close up photo of the area of the Duet around the fan connectors, so that I can see the fan mosfets?

@dc42

I finally got home and around to taking that photo. Its hard to tell, but it appears they fan mosfets may be blown.

0_1528925498974_C71684B4-26D3-4BC5-A886-85250E4A2DB6.jpeg

dc42

The photo is a bit out of focus so it's hard to tell, however it looks to me that TR5 has an indentation towards its right hand side which is typical of a blown mosfet. I can't tell whether the others have or not. If you are using a phone camera, try holding the phone a little further away to get the mosfets in focus, then use zoom.

Are they ordinary brushless DC fans, or some other type? Have they ever been connected to the fan outputs with the wrong polarity?