Here's a quick checklist of items to review and answer prior to sending SkyFi for RMA:
1) Has the unit been dropped at any time?
2) Hold the unit and move it around in a figure eight motion slowly. If you hear movement inside the unit then a component has come loose. This could be related to #1 above.
3) Fully charge the unit, then do a full reset.
4) Power on the unit and log into its embedded web page.
5) Connect to a telescope mount and test using SkySafari. Preferably check both rs232 and usb!
6) If the firmware is older, flash with the latest firmware available.
7) Fully reset and then re-test the unit with telescope mounts.
When sending for RMA after these steps result in failure, provide any other information you can from what you observe about the unit.