Originally Posted by
bergerud
As far as I know, the depth calibration is really a board thickness calibration and it does not have anything to do with your problem. If the bit touches the bit plate and the top of the board, the bit should carve properly into the board. If it does not, then there is a software or hardware problem.
Since you have reformatted the card, software would seem to be eliminated, unless, it is the card itself. Trying another card would be good.
You should check that the z encoder is working properly. It could have dust in it or the encoder disk could be damaged or loose. The FFC ribbon or its connections could also be the problem.
Another possibility is that the factory z calibration has been forgotten by the EEPROM. Only LHR can help if that is the case.