Erratic driver behavior with Duet 3 Mini 5+
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I've been using my delta printer powered by a Duet 3 Mini 5+ for a year and a half. I made two successful prints yesterday, but today it suddenly wouldn't work.
Homing didn't work – motors didn't move and I eventually got "Error: G0/G1: insufficient axes homed". I tried rebooting things and upgrading the firmware, but nothing seemed to help. Then I noticed that all drivers in M122 were listed as "not present", which doesn't seem good.
I browsed this forum for a while trying to find similar issues when I heard the typical sound of energized stepper motors. After a few seconds, one of the motors seemed to move slightly spontaneously. M122 now reported drivers 1, 2 and 3 as "ok". After a short while, drivers 0 and 4 were now "ok" and 1–3 were "standstill".
The motors were now making louder noises than usual. I tried turning ATX power off and on, and I was now back to all drivers being "not present".
I haven't made any changes to my electronics or anything for months, so it was surprising to see this happen so suddenly. I don't see anything indicating failure on the board; no little burn marks on chip packages or anything like that.
Any ideas about what could be wrong? Anything I could try for troubleshooting purposes? Has my board destroyed itself? I've attached three M122 responses with the different driver states.
Thank you!
M122-nonepresent.txt
M122-threepresent.txt
M122-fivepresent.txt -
@tomasf check the main fuses?
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@jay_s_uk Good idea! Both fuses seem fine, though. Near zero resistance.
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@tomasf are you able to get a good high res picture of the board. Specifically we are looking for anything odd around pins involved with communication with the stepper drivers over UART.
If you download the .ibom file form here:
https://github.com/Duet3D/Duet3-Mini5plus/tree/main/v1.01you can see a graphical representation of the board. you are looking for debris that could be shorting in the region of U9:
or this corner of the processor:
If there is nothing there then its probably an issue with U9 or the main processor
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@T3P3Tony Thank you for that info!
I tried to get good photos of the area, but the lighting isn't ideal and U9 is really tiny.
I did however spray some some canned air around the area and the main processor as well as dab some blue tack around to catch debris. I'm not yet sure if that actually helped or if it's just a temporary fluke, but the steppers now work fine, the drivers report OK with no read/write errors.
I'm now successfully printing! Let's hope it continues working. Thank you for the help!
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@tomasf maybe there was a metal shaving stuck on the chip pins causing a short circuit intermittently.
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@tomasf glad that worked. I am going to mark this as solved for now, feel free to reopen if it turns out not to have been something conductive shorting that IC
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