MCU Timeout on connect

[erik.zweigle]

Printer Model

Voron Zero

Extruder Type

Orbiter

Cooling Type

Afterburner

Hello,

My printer stops abruptly at random times 50% to 75% through a print. I cannot recover it through the web or klipperscreen. I need to power cycle. I thought it may be overheating because I transitioned from PLA to ABS recently and the build plate being 100°C so I swapped in a rear cover with perforations and added a larger fan to allow it to ventilate. But it quit again mid-print, and this time with PLA as I was testing the changes. Attached are excerpts from the klippy.log & moonraker.log files. I'm not sure how to read them but I think mcu timeout means a loose cable from umbilical PCB to Raspi4? Has anybody else had a similar problem?

=======================
Extruder max_extrude_ratio=2.078758
mcu 'mcu': Starting serial connect
webhooks client 4128911408: New connection
webhooks client 4128911408: Client info {'program': 'Moonraker', 'version': 'v0.9.3-0-g71f9e67'}
mcu 'mcu': Timeout on connect
mcu 'mcu': Wait for identify_response
Traceback (most recent call last):
File "/home/voron/klipper/klippy/serialhdl.py", line 68, in _get_identify_data
params = self.send_with_response(msg, 'identify_response')
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/voron/klipper/klippy/serialhdl.py", line 262, in send_with_response
return src.get_response([cmd], self.default_cmd_queue)
^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
File "/home/voron/klipper/klippy/serialhdl.py", line 319, in get_response
self.serial.raw_send_wait_ack(cmds[-1], minclock, reqclock,
File "/home/voron/klipper/klippy/serialhdl.py", line 254, in raw_send_wait_ack
self._error("Serial connection closed")
File "/home/voron/klipper/klippy/serialhdl.py", line 61, in _error
raise error(self.warn_prefix + (msg % params))
serialhdl.error: mcu 'mcu': Serial connection closed

 

[erik.zweigle]

Here is the latest disconnect log files from today during some testing of a matchstick LED add-on. The random print was with PLA. It definitely did not overheat. I am still at a loss as to the root cause. I'd appreciate any informed pointers.

 

[erik.zweigle]

I disconnected the flex cable from the Pi that ran to the toolhead accelerometer. Even though I did not have it connected at the toolhead I had left if curled up in a corner while printing. I also cycled the 5V/GND terminals on the Pi that come from the SKR Pico and rotated them in their socket after noticing one edge is ribbed on each pin. Just documenting here so I remember what I've done going forward.

 

[erik.zweigle]

Failed again, 2 hours into a 3 hour print. Log files attached. I don't even know if 'mcu' is referring to the raspi, umbilical, or toolhead pcb. Going to buy new cables and SD card now.

 

[erik.zweigle]

Came across a thread where someone said that his timeout issues were resolved when he stopped updating Klipper in his Machine Tab in Mainsail. He recommended using the identical FW revision across all MCUs. I've updated my hardware to be the same revision and will try this before ordering new cables.

 

[Rusty105]

Came across a thread where someone said that his timeout issues were resolved when he stopped updating Klipper in his Machine Tab in Mainsail. He recommended using the identical FW revision across all MCUs. I've updated my hardware to be the same revision and will try this before ordering new cables.

Did this fix your issue? I am having the same, or similar, issue.

Newly build V0.2r1 having mcu disconnect issues.

Starting to wrap up the build of my V0.2r1, LDO kit, and I am running into a frustraiting issue with klipper losing connection with mcu 'mcu'. It doesn't happen on smaller prints, maybe 30 minutes or less, but anything more than that it is like playing roulette. Half way through a 3 hour print...

forum.vorondesign.com

 

[erik.zweigle]

I haven't been able to confirm this fixed it or not. I have only printed two or three small items since then. The problem hasn't repeated since matching FW revisions but the testing hasn't been extensive. I also came across a guy in a FB forum who I recommended this solution to and he said it didn't fix it for him. He said that he had to disable his Crowsnest USB camera by selecting the power icon in the top right corner of Mainsail. So, I've been sitting on this information and waiting to see what I would need to do next. My arducam is connected via CSI cable so his problem and mine might be different. Either way, my larger non-voron printer doesn't give me problems so I tend to go with it instead.

 

[Rusty105]

Hmm.... I also enabled crowsnest, but not sure it got configured correctly as I didn't get my camera to work. I may uninstall that and see how it goes....

Thanks!

 

[erik.zweigle]

In the middle of a print I happened to be at my bench in the garage and watched the printer reboot in the middle of a job. I got excited, pulled the klippy-11.log and found... nothing. It just didn't have enough power and cycled itself with no warnings issued. So, I figured the Raspi4B needed its own dedicated power supply instead of pulling from the umbilical board which in turn pulls from the SKR Pico which in turn pulls from the 24V PSU. I bought a Meanwell 5V/5A 25W and made it fit in the rear. Ran three jobs and was coincidentally in front of it again when it stopped. Klippy-12.log shows mcu timeout on connect again. Super disappointed with my V0. I tend to avoid printing with it because of this.

 

[erik.zweigle]

Klippy-11.log

 

[erik.zweigle]

I've deleted a bunch of features that I was not using, following this guide: https://www.dzombak.com/blog/2023/1...re-to-help-keep-your-Raspberry-Pi-online.html. Will see if this makes any difference.

 

[erik.zweigle]

Still failing with "Lost communication with MCU 'mcu' ". Bought a new USB A to USB C cable to test out tomorrow. https://www.amazon.com/gp/product/B08W28GQ4P/ref=ppx_yo_dt_b_asin_title_o00_s00?ie=UTF8&th=1