Head 1 (L) Axis driver stops when running job

[alphaomega16]

Please provide information about the board with the issue:

• Is this issue based on a BETA Board, or an actual release motherboard design?: Release Board
• What is the revision number of your board, including the commit number? It should be on the front of your board ex. "REV03 BETA-5e1da24" or "REV03 156fadc": REV03 156fadc

Talk about the issue you're having here:

• What isn't working? Head 1 rotation axis stops working. Motor can be rotated by hand without resistance. Head 1 axis works on board reset, Will home without problem, Will rotate manually using the OpenPNP GUI. Once starting a Job will rotate 1 part then the driver stops. Works for quite a while and has progressively gotten worse.

Problem began as some parts being rotated -> vision checked -> then during final move placement will rotate ~30 (Always clockwise and during the Z move). Rotation motor has reached >160F (measured using Flir camera All other motors are cool) Actually caused deformation of PLA printed mount. One oddity worth noting: When placements would rotate during Z move the vacuum motor would slightly sound like it is slowing down (not enough power). This final movement involves rotating all 5 motors while running the vacuum pump (Highest current event). Running the provided 3A power supply.

• What does it prevent or degrade? Rotating parts

• What have you done to diagnose that it is a hardware issue? Must reset board (power cycle usually) to get the drive to function again. Swapped motor drivers, no change. Using known working placement jobs. Updated Firmware on Board

• Attach supporting files like software logs / scope images / logic captures / annotated schematic or pcb drawings.

Talk about how you think this should be fixed.

• What does the fix entail? Don't Know
• Have you been able to test this fix?

[alphaomega16]

Some updated information: Was able probe the board a bit and may have located the problem; On initial boot and homing the EN pin on the driver is pulled low (As expected). All is working well. After starting a job a part is only partially rotated and the drive stops working. In this condition the EN pin is now at 3.3V on only the rotation (L) Drive. All other drives are still pulled low. Further testing shows the DIAG pin is also pulled high at the same time the EN goes high. Based on the driver documentation this suggests a problem with the rotation motor.

I have purchased a replacement motor (and 2nd head components) and will update once it arrives.

In addition, based on recommendations here: Marlin: Stepper motor current setting for I & J (Z rotation) axes is too high I will be updating the firmware with a lower drive current to possibly reduce motor temperatures and future failures.

[alphaomega16]

Final update: Replacement rotation motor installed without improvement. Replaced rotation motor cable and problem appears to be resolved. From what I am able to discern, the cable has an intermittent break. When head moves to the approximate placement area the connection fails. The motor back rotates due to a twisting of the vacuum hose.