OK so you press the z axis button you get a whining sound and the table does not move up or down Correct. So I would check and make sure the Belt/chain is not slipping or has fallen off the drive train, check the motor to see that it has enough power to turn the 4 screws that the table moves up and down on.
You mentioned ajusting z axis acceleration , I'm un aware of this adjustment as Like I said its a manual adjustment you push an up or down button to make the table rise or fall. No speed adjustment seems necessary