Problem: The telescope is stuck.
Solution: Sometimes you may try to track on object as it approaches the horizon, or to aim at an object that is near the horizon. Aiming it to low will engage a factory default setting which causes the telescope to become non-responsive in order to protect the telescope. This is great for the scope, but might scare you. There is an easy fix. Go inside the dome, and look on the telescope's mount. On the east side, there is a key in the telescope, near a button that says something like, "horizon lockout override". Push and hold this button while someone in the control room tries to slew the telescope somewhere not so close to the horizon, such as the park location. Once the scope has moved away from the horizon, you can safely release the button and continue your session.
Problem: The Dome won't line up with the telescope.
Solution: IF THE DOME IS very FAR FROM ALIGNMENT - Manually turn the dome to face as closely in a cardinal direction as possible (N, S, E, or W). Now, on A.C.E. click the Dome drop down menus and make sure Auto Dome is turned off, then click "Reset Encoder". The dome thinks it is pointing in the direction labelled, "Dome is currently at azimuth". The azimuth in the North is 0, East is 90, South is 180, West is 270. Set the "Reset dome to azimuth" to one of the angles listed above corresponding to the direction you chose to aim the dome. This should get you close the alignment of the telescope. Now see the next section.
IF THE DOME IS only slightly FAR FROM ALIGNMENT - Go up in the dome, and look at its relationship to the telescope. you know that one rotation of the dome is 360 degrees. Try and guess how many degrees ahead or behind the dome is in relationship to the telescope. Now, on A.C.E. click the Dome drop down menus and make sure Auto Dome is turned off, then click "Reset Encoder". The dome thinks it is pointing in the direction labelled, "Dome is currently at azimuth". If the dome is ahead of the telescope add the estimated degrees to the current amount in the "Reset dome to azimuth".
Problem: 'Camera 2 failed to open'
Solution: Restarting the camera computer and turning on and off the CDD/QSI power strip fixed the problem (on the third attempt).
Problem: The telescope isn't tracking.
Solution: In A.C.E, under the Instruments tab click Auto Guider Display and make sure the Auto Guider 'On' button is selected.
Problem: Red Dome light will not turn off from manual switch.
Solution: In A.C.E. under the Instruments tab click Filter Wheel, then navigate to the Relay Box. Both boxes should be unchecked. "Relay #1" controls the white lights and "Relay #2" controls the red lights. The dome lights are controlled from both the manual physical switches near the stairwell to the telescope and via the telescope computer in the form of a relay switch. The computer control overrides the physical switch causing the light to stay on even if the physical switch is flipped in the "off" position.
Problem: Guiding is oscillating or drifting/can't center in one direction.
Solution: First check that the guider is on. It will turn off when you slew to a new target. The first and easiest answer is to try and pick a brighter star to track on. If it is still on, and no other brighter star exists in the field, essentially you're going to have to mess with some of the settings. The two things you can mess with is the gain on ACE and the max move X/Y.
The gain can be found under the guider control window in ACE (same place you turn it on). You may have to turn off guiding/stop and restart taking pictures with the guider if it doesn't seem to change anything when you initially change it. This will change the guiding in both the X and Y directions, but if you are only having an issue with one direction, try the next step.
The max move can be found in the guider window->Settings->Advanced. This is essentially the maximum amount of time you allow the motors to actuate to adjust the telescope. Thus, a higher number is going to let it move more than a smaller number. If it is simply drifting, first pick a relatively large value (around 2-3. Check that the values on the ACE guider window are going up to or close to that number for that direction, otherwise you can just stop and restart taking guider images). As it moves towards the center, turn it down to a low number (1-2). If it oscillating, use a smaller number to help it not move so much in between images i.e. overshoot the center. I believe overshooting is what's causing the oscillation, so your job is to help guide it in to the center, like guiding a ship into port.
Other tips: Shorter exposures help, but try to only use when your guide star is bright. The calculations for where it is going to move is based on the brightest pixel, so noise can have a significant impact in low light exposures. Don't waste too much time trying to guide; the telescope tracking is generally fine for most purposes, as the accuracy that KELT needs, for example, is *extremely* difficult for us to achieve.
Problem: The dome will not move, but the shutter can still open and close.
Solution: Right next to the big dome control box, about knee high, there is another gray gray box. Open it and push the red 'reset' button.