Dead driver or dying board?

dc42

@kazolar M906 reports the configured current. The actual current may be lower than reported by M906 when the motors are not moving, either because of driver standstill current reduction, or because of RRF idle detection.

Did you ever run the test i described in this post https://forum.duet3d.com/post/355556 ? That checks for an unlikely error condition that the firmware doesn't check for.

kazolar

@dc42 yes M569 P5 R1 or in my case M569 P0.5 R1 shows no response -- I had the same issue reproduced on driver 3 also, I tried M569 P3 R1 and M569 P0.3 R1 -- no response. Tried on rc1 and rc3, no response.

dc42

@kazolar ~~why are you using the R1 parameter with M569? That parameter is for use with external drivers, and should not produce a response.~~

OK, my bad, I made a mistake in my post. The command to use is M569.2 not M569.

kazolar

@dc42 ok, I plugged the 2nd carriage into driver 3 -- it's set for 2 amps, but I can move it by hand easily
This is what I have in config
M906 Y1600:1600 U1600:1600 X2000 V2000 W2000 A2000 Z2000:2000:2000:2000 E750:750:750:750 I50 ; set motor currents (mA) and motor idle factor in per cent
5/23/2025, 1:18:38 PM M569 P0.3

Drive 3 runs forwards, active low enable, timing fast, mode spreadCycle, ccr 0x10024, toff 4, tblank 2, thigh 200 (375.0 mm/sec), gs=39, iRun=31, iHold=21, current=990.234, hstart/hend/hdec 2/0/0, pos 232
It didn't apply -- it was ignored. When I had V mapped to driver 0, it was reporting 2 amps.

5/23/2025, 1:19:19 PM M906 V2000
5/23/2025, 1:19:26 PM M906 P0.3
Drive 3 runs forwards, active low enable, timing fast, mode spreadCycle, ccr 0x10024, toff 4, tblank 2, thigh 200 (375.0 mm/sec), gs=79, iRun=31, iHold=21, current=2005.859, hstart/hend/hdec 2/0/0, pos 232

5/23/2025, 2:06:08 PM M569.2 P0.3 R1
Register 0x01 value 0x00000005

M569.2 P0.3 R1 V7

M569.2 P0.3 R1
Register 0x01 value 0x00000000

I'll try to reproduce it, but it requires a print of some sort, I'll try doing a number of test cycles with V axis mapped to driver 3

dc42

@kazolar thanks. This really doesn't sound like an issue with the stepper driver chip to me, which is why I'd prefer to identify the cause and rule out (or otherwise) a firmware issue.

dc42

@kazolar motors are not powered initially when you power up the system. if you enable the Y driver using M17 Y does the motor become hard to turn?

jay_s_uk

@kazolar said in Dead driver or dying board?:

M906 Y1600:1600 U1600:1600 X2000 V2000 W2000 A2000 Z2000:2000:2000:2000 E750:750:750:750 I50 ; set motor currents (mA) and motor idle factor in per cent

This line is wrong. You can't set a drive current per motor on an axis, only on extruders.

This would be the correct line to use

M906 Y1600 U1600 X2000 V2000 W2000 A2000 Z2000 E750:750:750:750 I50 ; set motor currents (mA) and motor idle factor in per cent

dc42

@kazolar it's as @jay_s_uk says; however the extra values you provided in the M906 command should be ignored and the first value provided should be used for all motors on that axis.

kazolar

@dc42 ok, all being the same -- Z wasn't ever the problem, and extra prams are ignored -- the issue was easier reproduce on my secondary X carriage (V axis) in this case there is no risk of damage to the machine -- carriage just doesn't home properly -- but as per usual it doesn't want to reproduce now. I'll keep trying today -- but gonna run out of time. New boards are coming tomorrow, so if the problem re-appears, I'll update the post.

kazolar

@dc42 just wondering. Is it possible that M906 implementation has changed and the impact is only on the main board, not the expansion boards, so my extra params are screwing up current assignments? Hence setting current on the expansion boards is working fine, but main board -- it's not, or at least not correctly (timeouts in triple digits on the main board are still unexplained though)