In general, following each instrument intervention, a full complement of calibration frames (darks, flats, wavelengths, linearity, distortions, fibre-fed HCAO, telluric standard star, PSF star, and pupil images) are obtained. A multitude of parameters for each of these calibrations are scored and compared to their values prior to the intervention.

• Pre-optics motor issue Sept. 2017,
• SPIFFI upgrade:Dec 2015- Jan 2016,
• DSM installation on UT4:Oct-Dec 2016.
• Filter wheel problem: operating mostly in H+K and K between february and september 2013,
• Preventive maintenance (AOF installation):March-May 2015,
• SINFONI dismounted from UT3 (to be mounted on UT4):March 2011.