conk out 
phrasal verb with conk verb [ T ]  informal humorous uk/kɒŋk/ us/kɑːŋk/
  informal         
 (车辆或其他机器)突然出故障,停止运转,突然失灵
If vehicles and other machines conk out, they stop working or fail suddenly.
  I was just two miles from home when my motorbike conked out! 我出门刚骑了两英里,我的摩托车就突然出了故障! 
  倒头睡去;突然不省人事
to go to sleep very quickly, or to suddenly become unconscious
  After a six-hour flight and a long day of meetings, it's not surprising you conked out. 坐了6个小时的飞机,又开了一天的会,难怪你倒头就睡着了。