Our G30E-5 is only about 2 years old. While running, it will all of a sudden have a high pitch alarm like it is parked without the ebrake engaged and then stop. The engine stillruns but the lift doesn't move. IF you shift it out of gear then back in gear, it usually starts working again. If it doesn't , you have to put it into neutral, turn the engine off, wait a couple of minutes, and then turn back on. it will run for a short time and do it again.