Z calibration fails on central points  

RE: Z calibration fails on central points

Debris under the steel sheet?

RE: Z calibration fails on central points

No debris, all clean...

RE: Z calibration fails on central points

Your write: I tried to recalibrate it but I've got an error after the procedure. Question: Is the error on the LCD?What text?

Check your cables. Maybe the cable of the PINDA is broken. Move cable and see if the LED of the PINDA goes on and off.

Frans

RE: Z calibration fails on central points

Have you tried just switching off and letting it sit for ten minutes and then powering up again? Sometimes it just needs a restart after a failure to get everything back to normal.

RE: Z calibration fails on central points

The error on the LCD is to check if there is debris on the noozle, and the calibration fails.

I checked the PINDA sensor, the led is ok when I'm near the sensor with a cutter.

Is it possible that the bed suddenly fails in giving the correct contact to the sensor only in the middle zone? 

RE: Z calibration fails on central points

Check you Y axis drive pulley; there may be a string of plastic wrapped around it causing incorrect Y movement.

Also, ensure that there is a small gap between the pulley and motor body; any binding will also do the same.

Check the belt tightness and ensure the bed moves well in Y direction.

If all is OK, then check the PINDA.  Raise Z to about half-way. Go to the sensor status on the LCD and move the extruder left and right; trigger the PINDA at different positions using a screwdriver and check both the PINDA LED and the LCD PINDA status to ensure they are both in the correct state.  Your problem will probably be PINDA cable, when the extruder is close to the right hand edge of the bed.

Peter