Factory Core One Y-axis and homing failure after ~60 successful prints  

Factory Core One Y-axis and homing failure after ~60 successful prints

After successfully printing a job last night, I turned on my Core One this morning and out of nowhere it just will not pass the homing or Y-axis tests.

I have done all the recommended fixes:

• Belt tension is spot on the correct values(98/92).
• The gantry is perfectly flush with the stops(both front and rear) on both sides. I cannot even see light through the gaps while squeezing the opposite side.
• I have inspected all the belts, pulleys and gears, and everything it seated correctly, clear of debris and otherwise normal.

Whenever the printer does the Y-axis test or homing test(which is for everything...), it correctly probes both the X- and Y-axis stops in the front right corner with a clear banging sound, but then proceeds to do the fine calibration in an area between 5mm and 15mm from either stop over and over until the printer reboots with the red error screen. Isn't it meant to probe for the stops during that part? I could have sworn that before today it would just jerk back and forth a few times, clanging on the both stops and then it was done. Now it almost looks like it is probing for the stops in an area WAY to far from either stop and just gives up when it cannot find them.

In case the printer had saved a bad "expected area" to start probing for the stops, I did a factory reset and tried to run though all the calibrations again. But same issue. Every test passed except the Y-axis calibration, because homing fails.

I did have an extruder crash several days ago, when the extruder bumped a piece of support. The printer didn't detect it and just started printing slightly offset in Y, but I heard it and aborted the print when I saw what happened. But it has printed nearly a dozen successful prints(and homed correctly many more times) since that with no issues.

What the heck happened? How do I fix this?