detected by the two upper cameras 20 the computer also connected to the upper cameras 20 again determines a positional difference between the measured positions of the markings 12 and predefined required positions of the markings 12 these required positions apply to a position in which the contacts on the topside of the substrate lie directly below the corresponding test needles 6 of the test socket 5 it must now be determined again in step 30 whether there is a positional difference should no difference be detected between the required position and the measured position of the markings 12 the process can continue with step 32 otherwise the nest 7 is moved in step 31 by the determined positional difference this is again carried out by the high precision drives of the x y carriage 14 and the rotary drive when the contacts on the topside of the substrate 1 are now exactly below the test needles 6 of the test socket 5 the lifting post 15 is activated in step 32 and the nest 7 is moved upwards on the z axis until the test needles 6 of the test socket 5 are pressed with a predetermined force against the contacts on the topside of the substrate 1 it is not until now.