it is an older model no.nnt218g i was told it could be the defrost timer or the fans. it worked when we first got it home from the guys garage. and yes we let it sit upright for 24 hrs before plugging it in. and it worked great. then one day it shut off and wouldn't restart. i tried moving the thermostats not a twitch i will try a capacitor next but what i really need is a repair manual. i am a visual person.