motor phase A may be disconnected reported by driver(s) 0 1 2

garlicbread

I noticed after a while use my 3d printer I was getting the error
"motor phase A may be disconnected reported by driver(s) 0 1 2"
Then I'd end up with a large grumbing noise coming from the steppers as it was trying to home

If I then left it for a while then came back to it, everything would be fine.

I then stumbled across this thread
https://forum.duet3d.com/topic/10233/motor-phase-a-may-be-disconnected-reported-by-driver-s-0-1-2

I think I may have figured out the cause, I think it may be due to overheating on the duet board some place
ether the stepper drivers or main mcu, since I don't yet have active cooling over the board
and it's close to the heated bed.
I figured I'd just post this here in case anyone else was running into the same problem

Phaedrux

It could also mean that you have a loose wire, though it would be odd for 3 stepper wires to suddenly get loose all at the same time. Though if it were over heating of the drivers there would likely be errors to that effect instead of driver disconnection. What motor current are you using? Active cooling usually isn't required unless you're running in an enclosed space or using very high motor currents.

If you check M122 you should be able to see the MCU temps which should give a fair idea of the overall board temps.

https://duet3d.dozuki.com/Wiki/Mounting_and_cooling_the_board

garlicbread

I understand what you're saying but I don't think it's a loose wire.
The reason being I'd been using my printer all day running calibration prints, then towards the end of the day it suddenly started happening with the motors repeatedly, even after a power cycle.

I noticed just leaving it over night then trying to do a homing cycle (delta printer) worked fine again.
The motors are fairly small nema 17's set to a current of 1A

I did notice the MCU temperature was up to around 40 something degrees on the web UI when it was failing at the time (maybe 42 or 45)
(for info I had calibrated the MCU temperature long before hand, since I remember the docs mentioning that's needed to get an accurate reading)

I think it's my own fault for having the control board too close to the heated bed to be honest.