1. Is the light on the top of the P.I.N.D.A on ? If not, check the connection on the RAMBO board. If so, double check where it's plugged in.
2. Check the height on the P.I.N.D.A. sensor? Make sure it's the same as the directions.
3. When calibrating, is it directly over the first circle? I had an issue where the x end stop was a little off which caused the whole X access to be shifted a little
4. Make sure the pulley on the X stepper motor is not loose.
5. Update to the latest firmware. 3.0.6 and run the X/Y test.
Hope this helps.