GBT Troubleshooting

Focusser won’t Focus

Warning

TA or OS Only should physically handle the focusser

Note

This is very problematic, there are various strategies.

Note

Strategy 1: Resetting the Focusser

• Close FocusMax and CCD Soft on the Computer

• At the telescope, check the focusser is unlocked

• Use the focus hand control to drive to “physical zero”

  • i.e. there is no gap where the focusser moves outwards

  • ignore whatever value is on the hand controller

• Unplug focusser - breathe - plug back in

• Check focusser control now reads 0000

• Re-open FocusMax

  • Focus should move to last set value

  • Check value in FocusMax

  • Check value matches on manual control

• Re-try Focus

See also

There is no promise this works. If focus max attempts to go backwards (i.e. to 9999 and downwards) then you will need to try again.