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Trouble shooting

A sudden large area of reduced sensitivity

If the area is moving most likely it is a bug or spider. The only way to remove "a bug with wings" or a spider during an observing run is to lower the instrument and remove the offending bug. Contact staff!!!

No guide star

  • Check guide probe limits
    The telescope CCD-probe might be vignetting the guide star, if the guide probe has X > 100000 and Y < 50000.
    If you can't see the guide star check the guide-probe X & Y and choose a new guide star from here
  • Check that the TV-focus is close to 430
  • Check the TV-filter.
  • Perhaps there are clouds?
  • Is the mirror cover open?
  • Is the upper hatch open?
  • Maybe the lower hatch is vignetting?

Targetoff or imaexam problems

Symptoms: When running imexam or targetoff

  • instantaneous crashing and exiting
  • when no apparent imexam running, the cursor on ds9 is round instead of a cross
  • mosca.killpostprocess

No signal on the CCD

  • Check the pickup mirror position, the status should be "Park"
  • Check the TCS focus, it should close to 23230
  • Perhaps there are clouds?
  • Check the filter positions, perhaps two filters on the beam?
  • Is the mirror cover open?
  • Is the upper hatch open?
  • Maybe the lower hatch is vignetting?
  • All pixels values are 0, reduce binning and/or integration time, over exposed image

FASU control

  • FASU control does not start
    • Check filter position see point 4)
    • You can start fasucontrol by "hand". In a terminal window, type fasucontrol-SEQ.