Continued from my last post about K1 Max XY homing issue... Can you provide good diagnosis to find the cause? - At the first self test after the first power-up, input shaper test was finished without any issues. - But, while the first auto-leveling test, gantry started to hit the mechanical limit. - All first self test completed with many loud bang... - XY homing does not complete normally. Gantry hits mechanical limit. (See the attached video) - I checked belt tension, I found two screws for tensioner are loose in both A/B side. In this situation, the tension should be maximum. It was around 170Hz over 150mm. - I adjusted belt tension. 110Hz, 90Hz, 170Hz over 150mm, gantry hits at the all tensions. - Input shaper test again. I noticed one motor oscillated normally, the other motor rotated in one direction. It resulted gantry moved diagonal direction, then hit limit. - Failed to print 3D Benchy... My loving Ender3Pro worked for long time, and it's time to replace. I hope this issue can be fixed. Thank you.