Purchased a Nexstar 4gt from Telescope-Service (great price- thanks to this board for steering me there). Alignment is fine, but when I try to go to a new object it keeps slewing, and that vertically. Any ideas? Suggestions?
Most likely a power supply problem. This invariably results in uncontrolled slewing.
If you are using the NexStar 4GT with batteries, replace the set and try again. However, batteries get used up very quickly with GOTO scopes, maybe just a few hours per set. Instead, purchase a 12V power pack or use a mains connection. Also, check that the power supply lead is firm in the socket (with scope switched off).
  