laptop boots but doesnt display

:cry
hello! please why is that when i remove and put back my Ram in my laptop it boots but doesnt display again?
like even now it has completely refused to display, last time i had to unscrew to the last screw and rebuilt before it came on and i dont want to do that again,please give me a solution to this trouble.
NB my Rams are ok.
thanks
my mark is NEC KH2

 

Could you please post the make and model of your laptop and which version of Windows you're running including service pack?

 

Firstly - when the pc doesnt display after you boot, it normarly coused by any newly attached hardware - eg. HHD, CD o your DVD/CR-ROM, USB etc. If non were found then check for any virus/malware infection or newly/recently installed softmare. Otherwise your display cable is brocken somehow

 

i opened the laptop and removed the cmos and it came on.