Duet 3 - bad driver? Is the board dying?



  • I have a fairly new Duet 3 board (purchased Jan 19th, 2020) in my Delta printer. The steppers where configured with:

    M584 X0.2 Y0.1 Z0.0 E0.3

    After about a month of using the board, I noticed that I was starting to get layer shifting in the print away from my "Y" tower. I checked the belts, moved the arms, etc. Still had shifting. So, I replaced the stepper motor. Still had shifting.

    ** 6 hours of troubleshooting not typed here **

    Finally, I decided to try and swap the X and Y motor connections to the duet board, and changed the config.g's M584 to:

    M584 X0.1 Y0.2 Z0.0 E0.3

    Suddenly, the layer shifting moved to be away from the X tower. So, I changed the connections again to:

    M584 X0.2 Y0.4 Z0.0 E0.3 ; move Y to '4'. '1' seems bad?

    ...and the layer shifting has appeared to gone away. (I've only run a single test so far. I wanted to get this message posted earlier in hopes of catching @dc42.)

    To me, this suggests a failure of some type on the driver for the "DRIVER_1" stepper connection. However, I'm not an electrical engineer, so was hoping to get some feedback on here. I'm including a picture that shows the shift. The left cube was printed while Y was attached to driver 1. The right cube was printed while X was attached to "driver_1". (traditional delta stepper lettering with X in front left, Y in front right, Z in the rear):
    20200229_150709.jpg

    I've also taken a couple of quick photos of the duet3 board in the area of the "DRIVER_1" connection in case someone sees some damage:

    20200229_150055.jpg

    Am I okay to continue to use this board as long as I avoid the driver1 connector? Should I ask filastruder for a warranty exchange? (Will duet approve an exchange?) I'm not sure what my next steps should be (if anything.)

    Thank you
    Gary



  • There is something that at a glance looks like a problem with Q9, but it could also just be dust and out of focus. If it brushes off then ignore, if not see if you can get a macro shot in focus please.

    (But ultimately if it prints fine with using say 0,2 and 3 thats indication enough that 1 is fried.)



  • There was dust on the chips. A bit of compressed air helped. Here's another crop of the area. There is some kind of discoloration on that chip in the photo, but I don't see it with my naked eyes, and it feels smooth.

    20200229_161627.jpg


  • administrators

    Have you switched the drivers into stealthChop mode? If so, please set them back to spreadCycle mode (the default on Duet 3) and test again. stealthChop mode on other drivers is known to cause missed steps under some conditions. Send M569 P1 to report what mode driver 1 is in.

    If it's already in spreadCycle mode, then my guess is that one of the output mosfets has either failed open circuit or has a bad soldered joint underneath. I'm also suspicious of the black disc on R202. I'm happy to approve a warranty replacement.

    [Note to Duet3D staff: please re-test in the ATE and check in particular the phase correlations for driver 1.]



  • @dc42 said in Duet 3 - bad driver? Is the board dying?:

    Have you switched the drivers into stealthChop mode? If so, please set them back to spreadCycle mode (the default on Duet 3) and test again. stealthChop mode on other drivers is known to cause missed steps under some conditions. Send M569 P1 to report what mode driver 1 is in.

    If it's already in spreadCycle mode, then my guess is that one of the output mosfets has either failed open circuit or has a bad soldered joint underneath. I'm also suspicious of the black disc on R202. I'm happy to approve a warranty replacement.

    [Note to Duet3D staff: please re-test in the ATE and check in particular the phase correlations for driver 1.]

    There's nothing attached to driver_1 at this point, but it was in the default spreadcycle mode. I did turn on "steathchop2" at one point a week or two ago, by manually setting it with the console, but couldn't find information on how to get the driver to self-calibrate itself (as I saw mentioned when googling 'stealthchop2') , so decided not to retain the setting and reset everything before printing. It was a case of "I'm not sure what I'm doing, so won't mess with it."

    Here's the output requested for both P0 and P1 (being that P1 is unused now):

    2/29/2020, 4:50:15 PM	M569 P0
    Drive 0 runs forwards, active low enable, step timing fast, mode spreadCycle, ccr 0x08053, toff 3, tblank 1, hstart/hend/hdec 5/0/0, pos 742, tpwmthrs 2000 (1.9 mm/sec), thigh 200 (18.8 mm/sec)
    
    2/29/2020, 4:50:09 PM	M569 P1
    Drive 1 runs forwards, active low enable, step timing fast, mode spreadCycle, ccr 0x08053, toff 3, tblank 1, hstart/hend/hdec 5/0/0, pos 8, tpwmthrs 2000 (1.9 mm/sec), thigh 200 (18.8 mm/sec)
    

    I'll contact filastruder to figure out how to go about a warranty exchange. Is there some kind of reference I should attach to the board so you know how to relate it to this issue for possible investigation?


  • administrators

    @garyd9 said in Duet 3 - bad driver? Is the board dying?:

    I'll contact filastruder to figure out how to go about a warranty exchange. Is there some kind of reference I should attach to the board so you know how to relate it to this issue for possible investigation?

    Yes please, put a tag or sticker on it giving brief details of the problem and a link to this thread.


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