Green light off



  • Hi,
    I have been slowly configuring my build as parts come in. This morning I noticed that the green 3.3V light is off and I cannot connect to my computer. Messing around with fans I somehow blew the 1A fuse. I actually noticed that my SD card had popped out and when I checked that on my computer I realised that the SD card was wiped. I reconfigured a new SD card but still can't connect the duet 2 Ethernet to my computer and still have no . I am quite distressed as these boards aren't cheap.
    I have disconnected all my printer hardware from the duet but still can't get the connection.nothing is getting hot. Everything was working fine yesterday. Please help!!
    Damien



  • Green light (3.3v) off usually means repeairs; if combined with the red light (5v) it might be a blown fuse but alone it is most likely the 3.3v regulator (U2 on the board, 3 pin part) blown.

    The 1A fuse is also just for the fans, not something that affects 5v or 3.3v, they're powered off the 7.5A fuse next to the 1A fuse. But again, if the red 5v light is on then the fuse is ok.

    With the SD card wiped as well its possible that the other 3.3v parts are also damaged (wifi/ethernet and main microcontroller).

    With nothing getting hot, you could perhaps measure the resistance between 3.3v and ground, if it is not a short, you could try an external 3.3v source to see if the rest works. Ideally a current limited supply set to 200mA.


  • administrators

    Another reason for the green LED being off is that you have connected the endstop switches to the Duet incorrectly and they are shorting out the 3.3V rail. So with power off, disconnect the endstop switches, then power up and see if the green LED is lit.



  • @bearer Thanks I will test the circuit and get back. I don't think the prognosis is looking great at this stage. I'm stumped as to what caused this. Most everything was connected and working well. The only thing I've been doing is adding 12v fans.



  • @dc42 All the endstops/BL Touch and most other printer hardware were already up and running perfectly. I just added a new 12v fan to cool a peltier module (not hooked up to the duet in any way yet). I did however notice that the micro SD had somehow popped out (god knows how or when). Could this have in some way affected the circuitry?(it sounds ridiculous even as I write it)



  • @dc42 I have disconnected all hardware from the duet. I just connected the duet to my laptop and noticed that the green light and the 'diag' red light flicker for about 3-5 seconds then fade to black.


  • administrators

    @genseric said in Green light off:

    @dc42 I have disconnected all hardware from the duet. I just connected the duet to my laptop and noticed that the green light and the 'diag' red light flicker for about 3-5 seconds then fade to black.

    That sounds as though something is overloading the 3.3v rail. Is anything on the Duet getting hot? The most likely candidates are the SD card, the chip on the Ethernet module, and the main processor.



  • @dc42 Nothing is hot. The 2 flickering lights have not come back on at this time either after plugging and unlugging a couple of times


  • administrators

    What's happening is that the laptop is shutting off USB power to the Duet due to excessive load. Try applying VIN power instead, and assuming that the red 5V LED lights up, then see what is getting hot.



  • @dc42 This is the only component getting hot
    IMG_1001.jpg



  • @genseric that would be the 3.3v regulator, and if it keeps getting hot without the SD card, you could try removing the whole Ethernet module and see if that makes a difference.



  • @bearer yeah, you got it bang on first time... and I have removed the ethernet module and the 3.3V light is on again!!! So... I just need to replace the module?



  • @genseric i'd test the other features using the usb console and/or PanelDue, then just order a new Ethernet module if everything else is ok.



  • @bearer Copy that! I will run some tests tomorrow and report back. Thanks heaps for your help and thank you @dc42. I really appreciate your time. I'm in Sydney and I believe that I bought the last duet 2 stock in Australia. Lets hope I can get a new ethernet module here.
    Cheers lads! You rock!



  • @genseric said in Green light off:

    I'm in Sydney and I believe that I bought the last duet 2 stock in Australia.

    ouch, that might delay things a bit. hopefully you can limp along with SD card and USB console or PanelDue until you get it replaced (if everything else works out)



  • I thought I'd follow-up on this post as I hate when people leave the thread hanging. I received my new (genuine) ethernet module from the US - I have plugged it in and everything is working as it should be. This is a timely lesson to me as I was getting lazy in turning off my duet when switching out hardware (fans in this case). I think I got off extremely lightly!
    Thanks again for the help.


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