On May 16, 2024, about 1330 Pacific daylight time, a Cessna P210N airplane, N4769K, was substantially damaged when it was involved in an accident near Daggett, California. The pilot was not injured. The airplane was operated as a Title 14 Code of Federal Regulations Part 91 personal flight. The pilot reported that, about 15 minutes after departing Kingman Airport (IGM), Kingman, Arizona, the primary flight display started to flicker and did not read correctly. While he was troubleshooting this problem, the radio and transponder shut off. He attempted to call ATC and he set the transponder to 7600. He soon realized that the radios and transponder were not working. The pilot then positioned the landing gear handle to the down position and confirmed from the landing gear inspection mirror that the nose landing gear was down and locked, but the main gear had stopped in a transient position. The pilot reported that he attempted to use the emergency gear extension handle, but was not successful. Subsequently, the pilot used an iPad with Foreflight and diverted to Barstow-Daggett Airport (DAG), Daggett, California, about 90 miles west of his location. The pilot landed with the main landing gear in the transient position, resulting in substantial damage to the left horizontal stabilizer and elevator. The mechanic reported the airplane was relocated to a hangar where it was placed on jacks. The mechanic switched the master switch to On and immediately the landing gear pump turned on, which was followed by the main landing gear moving to the down-and-locked position. The airplane was repositioned on the ground, and the battery was soon out of power. The mechanic stated that the landing gear emergency extension handle was down and stowed when he arrived. A few days later the mechanic prepared the airplane for an engine test run and found the alternator main circuit breaker had been tripped (opened). After resetting the breaker and turning on the split-rocker master switch, voltage was observed. The alternator belt was undamaged, and tight on its pulleys. The engine started normally and charge was observed on the ammeter gauge. With the engine running at about 1,700 RPM the voltmeter read 28.5 to 28.8 VDC with all lights and avionics working normally. During the test run there were no shorts to ground or defects noted. The mechanic reported that he could not duplicate tripping the alternator breaker during the test run. The landing gear emergency extension system was examined. The pump handle could not be extended from its retracted and stowed position. When the screw attaching the inner handle retaining spring was backed out the inner handle extended normally. No other anomalies were noted with the landing gear extension system.