Troubleshooting guide

We frequently monitor the middle dome temperature, but there is also a truss temperature monitor that the
telescope operator can read for you. It's advisable to watch the temperature every 30 – 60 minutes, and if
necessary adjust the focus on the TV camera.
A good starting point for the focus is the chart of f/8 focus vs. truss temperature, on the wall between
mayall-2 and mayall-3. A snowflake icon on the mayall-2 and mayall-3 desktops will display the telescope
truss temperature.
NOTE: If the focus changes a large amount (2000 units) from one night to the next, verify that the ADC
prisms within the guider are out of the beam. They have been known to move into the beam without being
expressly commanded to do so.
8. Check the display orientation. A raw FLAMINGOS image on the nominal ds9 display (no image flip or
rotation) has earth parity (E is cw from N), with the rotator position angle at the bottom of the display
(Figure 3).
Figure 3: Orientation of a raw FLAMINGOS image on the ds9 display for rotator angles of 90 and 0
degrees.
The snowflake icon on the mayall-2 and mayall-3 desktops will display the truss temperature.
The windsock icon on the mayall-2 and mayall-3 desktops will display the current weather at the 4-m
telescope.
You are now ready to start observing!
FLAMINGOS@4-m, Ver. 2.39, 2013 April 23 Page 17 of 47