Was that resolver mounted to a servo motor, and wired to the motor servo controller/amp?
It might require that it is "mechanically clocked" exactly as it was originally built in order to work correctly again. I would advise against separating a servomotor from its resolver, unless you are certain you can restore the exact relationship when you put it back together.
Does the motor seem to run correctly, and smoothly? And, the jackscrew (driven load) can't "find home"? If so, it sounds like there's an external home sensor/signal somewhere on the machine that didn't get put back right or has failed.
If it's truly a resolver, Peter is right as far as homing. They're absolute; the resolver decoder will derive the angle of the shaft...depending on the system which contains that decoder, you may or may not be able to offset that value in software, to match the motor shaft position.