開左機但個mon冇野出(急救呀!!!!!!)

有一日用用下hand左機,,我關左機之後重開,,但部機開到,,但個mon冇野出,,試過換過第二個mon都係咁,,咁既情況會係咩既問題????
有冇人教我e家要點做呀!?!?!?
換過mon線啦!!!
佢係部機開到,,,個風扇都有轉呀,,,但係就個mon話開唔到,,點算呀!?!?
唔記得左講,,係keyborad都冇燈,,個mon就係橙燈,,有冇人救我呀
咁如果要換又要幾錢呀?