====== Troubleshooting ======

This is a collection of information that has been useful in the past. Follow the links for more details.

  * [[cso:telescope:shutter]] won't respond? [[[[cso:telescope:shutter#troubleshooting|Reset]] the controller.  
  * [[cso:telescope:dsos:dsos|DSOS]] problems? See [[cso:telescope:dsos:userproc#troubleshooting]] tips.
  * [[cso:telescope:telescope]] problems? 
    * //SECONDARY MIRROR CONTROLLER ERROR// on the telescope status monitor? This may indicate the focus controller is confused. Try \\ ''__UIP__> **antenna /restart** ''
    * Multiple difficulties at the same time? Scans won't start, the telescope doesn't move, the spectrometer is hung up, scans stop in the middle of integration, etc. Try \\ ''__UIP__> **antenna /restart**'' \\ or \\ ''__UIP__> **antenna /restart /nosync**''\\ Do //not// press the //reset// button or power cycle the antenna computer unless you are certain a hard reset (powercycle) is needed. Further information [[http://www.cso.caltech.edu/docs/hiro/ant/reload.html|here]] or [[http://www.cso.caltech.edu/docs/troubleshooting.html|here]].
    * ''Tlength'' large? This is the angular distance between the dome and the telescope. It is small during normal operation so any significant value indicates a fault. A misalignment of 0.1° corresponds to ''tlength'' about 0.075. If ''tlength'' is positive, the telescope azimuth is smaller than the dome azimuth. The control system stops the telescope if ''tlength'' exceeds about 0.250.
  * Heterodyne [[cso:instruments:heterodyne:heterodyne|receiver]] problems? See [[cso:instruments:heterodyne:observing#troubleshooting]] tips.
  * For [[cso:instruments:sharcii:sharcii]], don't specify a  fixed focus (or X, Y, or theta) position. Instead use a focus offset with constant updates: \\  ''__UIP__> **focus /constant**'' \\ or \\ ''__UIP__> **instrument sharc2**'' \\ ''__UIP__> **focus /offset //NNN//**'' \\