In a GIF system, if the energy-selecting slit does not move in or out, then we need to check:
         i) The presence of pressurized air.
         ii) The pneumatic connections.
         iii) There should be puffs of air coming from the Gatan Instrumentation Bin (GIB) when the energy-selecting slit is moved in and out in the FilterControl software. In this case, the electronics controlling the pneumatics is working.
         iv) Apply a high pressure (≤ 100 N/cm²) to the white slit control hose going into the GIF to loose the o-rings if the GIF has not been used for a long time because the o-rings may stick.

If the pneumatic aperture in GIF system does not work, then we need to check:
         i) The presence of pressurized air.
         ii) The pneumatic connections.
         iii) There should be puffs of air escaping from the GIB when the aperture size in the FilterControl software is changed. In this case, the electronics controlling the pneumatics is working.
         iv) Apply a high pressure (≤ 100 N/cm²) to the colored hoses coming from the aperture mechanism to loose the o-rings if the GIF has not been used for a long time because the o-rings may stick.