Smart Effector Fans work/LED Lights Don't Light Up



  • Greetings --

    I've had the smart effector for about a month -- at one point, the 3 LED lights on the bottom end worked, but it was for a very brief time. Now, despite the fact that both fans work correctly, none of the bottom LEDs light up.

    NOTE: all status LEDs are currently working correctly.

    Thanks in advance for any advice....



  • Those LEDs are driven by the "hot end fan". They will only be on when it is running (not the part cooling fan).

    If you heat up your hot end, and the fan comes on (assuming thermostatic), what happens to the LEDs?

    Also, if I recall, there are some jumpers involved in this fan/light relationship... perhaps one got knocked off? Check the smart effector docs.



  • I appreciate your reply, but as I said, both fans work correctly. The hot end fan turns on when temp reached 45 and part fan turns on during print commands. I did originally set the 12v jumper and I do observe it still on here. I also have looked at the docs and that's why I'm reaching out to the forum. I believe that's what the forum is for, isn't it?



  • Yes, that is exactly what the forum is for, which is why I interacted and perhaps repeated some information that was already covered in your first post.

    Tone is really hard to read in written communication. If I somehow made you feel unwelcome or "talked down to" by being more explicit about fans and LED power, I apologize. My intent was to seek more dialog and see if a thought got triggered.

    Were it me... I'd dismount the smart effector completely and look very carefully with good magnification and lots of different angles of light, look at all the traces that lead from the top connectors to the bottom connectors for the hot end fan and the LEDs. Some of those are very easy to damage.

    Also, an ohmeter could potentially find something, with the board dismounted and disconnected.

    P.S. To be clear, I'm not Duet official in any way, just a guy that has a bunch of Duets and two smart effectors.


  • administrators

    The Smart Effector schematic is here https://github.com/T3P3/SmartEffector/blob/master/SmartEffector/SmartEffector_v2.0/SmartEffector_schematic_v2.0.pdf. The 3 LEDs and 2 resistors are all connected in series, that that chain is connected in parallel with the hot end fan. One of the resistors can be bypassed with a jumper. If you have a multimeter, you can check the continuity of that chain.



  • @dc42 Can you tell me how do i check for continuity and which jumper? i have the same problem.


  • administrators

    Use the schematic I linked to in my previous post to guide you. The jumper is the 12/24V one labelled "LED voltage select". The traces between the LEDs are easy to spot because they run along the edges. The resistors are the two largest ones not far from the jumper.



  • @dc42 i checked all the LED is working but i am getting resistance on the test. is this normal?


  • administrators

    @ken340 said in Smart Effector Fans work/LED Lights Don't Light Up:

    @dc42 i checked all the LED is working but i am getting resistance on the test. is this normal?

    Can you explain what you mean?

    If the hot end fan works but the LEDs don't, the following are the likely causes:

    1. Blown 150R series resistor, which will happen if you ran with 24V applied but the voltage select jumper was fitted as if you were supplying 12V.
    2. Bad PCB trace connecting the LEDs together. The traces run very close to the edge of the PCB, and sometimes when the panels of multiple PCBs were broken apart, the trace got broken. This should have been picked up in testing (and we have improved the PCB design since then). Here is an example of a trace that has nearly broken through:

    2020-08-13 10.04.48.jpg

    So use a multimeter to check that the LEDs really are connected together.



  • @dc42 I use a multimeter to the LED individually and they are in working condition. The continuity test returns with a value, Can I assume the circuit is not close, this may be an issue with the faulty resistor.


  • administrators

    @ken340 said in Smart Effector Fans work/LED Lights Don't Light Up:

    The continuity test returns with a value

    Please explain what you mean by that. What are you testing for continuity, and what value does your multimeter read?



  • @dc42 from the 12v/24v pin and i am getting a readout of 600+


  • administrators

    if you mean you are getting a reading of 600 ohms across the 12V jumper pins, that's normal because there is a 604 ohm resistor connected between those pins.

    Does the 150 ohm resistor look intact, and does it read 150 ohms?

    What PCB revision is your Smart Effector?



  • @dc42 the 150 ohms looks intact and i am getting 150 ohms reading. its v2


  • administrators

    I suggest you use your multimeter to measure the resistance between H+ and D1 (should be 750 ohms), between the other side of D1 and D9 (0 ohms), between the other side of D9 and D7 (0 ohms), and between the other side of D7 and H- (0 ohms).


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