Dont Post

Hey can someone please help?? I was useing this computer when all of a sudden after i shut it dn wont restart I am geting pwr to motherboard the two red lights on board lites up and theres power going to all componets just no green led.. Now heres what I have done I pulled the ram cdrom floppey drive video caerd sound card even change the pwr suply to a new p4 nothing on the motherboad excep for the ram ( yes the ram is good) pwr suply an video card still no post ram is new checked on anouther computer works great pwr suply is a 450 p4 new video card is a gforce new. Oh an I pulled bat to reset. This computer was woking great tell i shut it dn the rigt way start etc. and i also pulled the proser and checked it in anouther computer checks good. :( I thunk the moutherboard me it maker :(