When I do a master reset it leaves the east and west limit both on 5000 on my box. You can't access the menu to program any satellites until you have some range between the east and west limits. What I do is just highlight one of the 5000's, use the left and right arrows on the remote and when the dish moves the count moves. Once there is some range the other menus will be accessible but you still need to get the limits far enough apart to move to the satellites desired and do the programming.
If you've already done that and you can't get the count to change try the following:
You can test the arm with a car battery to see if it will move. I'd do the test right at the arm to eliminate any wiring issues that might be in play to prove out the arm but unhook it from the 922 first so you don't send power back into it from the battery. If it moves both directions you know it is OK. Reversing the wires from the battery will reverse the arm direction. If that works you need to go over the wiring carefully and check that power is coming out of the 922 to make the dish move and that it actually gets to the arm.
When you try to change the 5000 count from the 922 menu, do you know if the dish trys to move? If the 922 doesn't get a signal back right away it stops trying to move. If not, I'd check the wiring and see if power goes out when you call for a move. You can use the car battery from that end if you want to. If it does, the problem is probably in the count generating device or wiring. Make sure that wiring is right as well.
There are physical limit switches inside the electrical box on the end of the arm. They can be adjusted so the dish won't move but that seems pretty unlikely. Overall it sounds like a stuck or bad arm, bad wiring or both. Once you prove out that stuff the only thing left is the 922 which I'd assume is OK until you prove out everything else.
Good luck and be careful not to fry anything.