At 18:49 Pacific time, a Cessna 210K suffered a collapsed landing gear while landing at North Las Vegas. The pilot and passenger were not injured. The landing gear would neither fully retract nor fully extend after takeoff and the pilot elected to return to North Las Vegas. The accident flight was the first flight of the airplane following an annual inspection in which the landing gear was reported as having a discrepancy. The gear was re-rigged and the aircraft placed on jacks. Mechanics successfully cycled the gear 10 times using a external hydraulic pressure source. The accident flight was the first takeoff after the inspection. The emergency manual extension hand pump would not give a landing-gear-extended cockpit indication. Subsequent inspection revealed the engine-driven hydraulic pump was inoperative.