# Z axis no longer working on a working printer

I was printing an object and it started to drag so I stopped it.

Went to move the Z-axis up so I could clear the bed and Z-axis would not budge. I switched the printer off and manually turned the motors to get the Z up. Cleared the bed, switched on and homed the printer. When it came to home the Z, BLTouch deployed and then nothing. Motors will not turn.

Things I tried:

• Recompiled the firmware (Marlin 2.0.x)
• Different motors - Motors were free from the printer, just resting on a desk so I know it's not binding or anything.
• Swapped stepper driver with a known working one.

• CR10s
• SKR1.4 Turbo board
• TMC2208 Steppers
• BLTouch
• Octopi to control the printer.

Output of M122 for the Z:

Recv:       Z
Recv: Enabled       false
Recv: Set current   1000
Recv: RMS current   994
Recv: MAX current   1402
Recv: Run current   17/31
Recv: Hold current  8/31
Recv: CS actual 8/31
Recv: PWM scale
Recv: vsense        0=.325
Recv: stealthChop   true
Recv: msteps        16
Recv: tstep     max
Recv: PWM thresh.   0
Recv: [mm/s]        -
Recv: OT prewarn    false
Recv: triggered
Recv:  OTP      false
Recv: pwm scale sum 10
Recv: pwm scale auto    0
Recv: pwm offset auto   36
Recv: off time  4
Recv: blank time    24
Recv: hysteresis
Recv:  -end     2
Recv:  -start       1
Recv: Stallguard thrs
Recv: uStep count   40
Recv: DRVSTATUS Z
Recv: sg_result
Recv: stst
Recv: olb
Recv: ola
Recv: s2gb
Recv: s2ga
Recv: otpw
Recv: to
Recv: 157C
Recv: 150C
Recv: 143C
Recv: 120C
Recv: s2vsa
Recv: s2vsb
Recv: Driver registers:
Recv:       Z   0xC0:08:00:00
Recv:
Recv:
Recv: Testing Z connection... OK

• First I suspected this could be faulty Z motor cable (broken wire, etc.). The G-Code M122 is for communication with the driver board. There can be almost no feedback from motor itself (there are just 2 pairs of coil wires) ...almost, because we can see Testing Z connection... OK. But anyway, to be on safe side, did you doublecheck with multimeter that Z motor cable is properly conducting? (There is only one Z motor in this printer, isn't it?) Jan 24 at 19:35
– 0scar
Jan 25 at 12:13
• Sincere apologies for your question being temporarily closed - it was an admin error. Please add the "Update" as an Answer, even though it wasn't quite resolved, because putting the solution inside the question breaks the Q&A mechanism of the site. Many thanks. Feb 1 at 4:13
• For "suddenly have this issue" the only explanation I have is that of Z steps/mm set to 0, and could happen unintentionally (from LCD or with M92). (Unless someone recompiled firmware with changed settings, then it's suddenly no more.) So @Gaz83, could I propose to accept my answer and have this question closed already? Feb 2 at 4:03

It could be caused by software or configuration issue.

# Possibility 1: just worked after re-installation of Marlin

You could have Z steps/mm set to 0 in EEPROM, and did not notice that fact. It is possible to fix this unconsciously with Marlin software reinstallation, following the upgrade procedure which included reset of EEPROM settings - like "Step 4: Finishing touches" described in community wiki's guide for Updating Marlin Firmware. This is described in more details in another post No stepper motor movement on Ender 3 Pro.

# Possibility 2: Marlin configuration is not correct

When you recompiled Marlin, did you use already proven configuration for Marlin? When saying "Motors will not turn" you mean only Z? Are your other motors are still functional now after Marlin was deployed?

Among other Marlin settings, you may want to check that this line is disabled in Configuration_adv.h:

  /**
* Software enable
*
* Use for drivers that do not use a dedicated enable pin, but rather handle the same
* function through a communication line such as SPI or UART.
*/
//#define SOFTWARE_DRIVER_ENABLE


(I took this advice from No Motor Power With TMC2209 on RepRap forum.)

• Yes I used the copy I already had, just recompiled. Yes X and Y worked fine Jan 25 at 6:21
• Thank you for the feedback. And it is good to hear that you have resolved your issue. If you would like to find a root cause - then if reinstallation od software helped after you "deleted your Marlin" and "a fresh downloaded copy" worked better, then maybe there was a difference in (1) configuration or (2) the code (at least version of Marlin). If there are no justifiable differences, I have a very good theory - so I will improve my answer. Jan 25 at 20:14
• The only problem with possibility 1 was that the printer was running. It had homed and started printing. I then Paused using octopi (pause button, not in terminal) and then used the controls to try and move Z up and that's when it stops. So there was no M92, or any other commands, used. I appreciate the support. Feb 2 at 8:10
• Compilation errors happen. Feb 2 at 8:42

Issue seems to be resolved. I deleted my Marlin copy, downloaded a fresh copy and I started again.

What worries me is how a working copy and a working printer can suddenly have this issue. Feel like this issue could come back as I never found the root cause.