50% shift in Y axis in the mid of print - opinion needed  

50% shift in Y axis in the mid of print - opinion needed

Hi everyone,

I assembled my MK2 kit last weekend (14 hours) and the first PLA prints have produced amazing results with the preconfigured slic3r settings for 0.1 and 0.2mm. Particularly the print of the ctrlV v3 model from thingiverse was mindblowing 
This weekend I tried something bigger that utilizes the whole platform and in the morning I found the following mess (s. pictures). The issue should have occurred after ca. 8 hours of printing. It looked like a massive 50% offset in the y-axis. I was able to confirm this by using the real-time axis movement. After a power cycle and clean up I got “Motor Z - Endstop Y” error during selftest, which I rerun as a starting point of the investigation. Another power cycle and the selftest was passing. I guess it was caused by the y-axis offset. I visually inspected the wiring and it looked ok. Then I noticed that the PINDA probe was very loose. I fixed it (this time with locktite instead of nail polish  ) and reran the xyz-calibration. Then I tried to preheat and got a MINTEMP error with both thermistors indicating 0. I checked the one at the hotend and saw that one of the two wires was detached from the connector. Then I remembered that when I found the printer the nozzle was pressing strong against the cold model and the bed behind it. I guess this could have caused the PINDA and thermistor problem. Which makes me wonder what happened and what caused what... Unfortunately I don’t gave OctoPrint yet, but this is going to be my next step after soldering the thermistor connection. Any ideas, suggestions, hints?

1. What could have caused the 50% offset in the y-axis?
2. It seems that the selftest doesn’t check the connection to the hotend thermistor, is this correct?
3. Do you agree that if the PINDA gets loose later during the print process this will not cause an issue?
4. Do you agree that if the thermistor circuit opens during the print this will cause the FW to stop it immediately and thus could not have caused the issue?
5. Do you agree that if the thermistor circuit partially opens during print this will cause an increased resistance readings and thus will trigger a thermal runaway and immediately stop the printing process and thus is most probably a result from the issue and not it real cause?

I would love to hear your opinion.

Kind regards,
Dimo