LCD Screen Problem Vostro 1700

Hi guys i took apart my dell vostro 1700 laptop last night because the fan had stopped working
i followed this guide
How to take apart Dell Inspiron 1720 or Dell Vostro 1700 laptop >> Inside my laptop

and i went up until the modem part as i didnt need to take that off
anyhow i took it all apart put it all back together and woo the fan works
but one slight problem..

I turned the laptop on - no display from the screen.. then it showed a blue screen (which is my login screen) then it went off and now i just have no display
external display works via the monitor i plug in but no display from the lcd screen
So im wondering what it is? surly it cannot be broke? i was gental pulling the cables out etc.. from the motherboard and plugged them back in..

But also i had 2 take out the heatsink to get to the cpu fan and put it back and also the dvd drive.. memory.. wlan.. hard drive
and also i noticed when i run my computer now it says
invalid parition table on bootup?
So im confused - im not to worried about the invalid parition because that may fix if i reinstall windows ( which i need to anyway) but the monitor aint working and i really am clueless on what todo? iv'e checked that everythings plugged in correctly?

What do you all suggest?


EDIT #; i noticed when i turn the laptop on the screen goes darker than it is then goes back to normal colour when its turned of


Another Edit:

When i plug it in via external monitor and then it says invalid parition table and then i press cntrl alt delete to restart it the monitor lights up with a underscore then goes back to being black
so theres gotta be something wrong here i dont think its the monitor maybe i need to reset something??

 

Well no POST is a completely separate issue. Do you have the Nvidia or Intel graphics? For Nvidia, the LVDS cable plugs into the graphics card, Intel graphics it plugs into the motherboard. There is also another LCD cable that plugs into the motherboard which has pins. If you aren't careful, you can ruin the motherboard.

A blinking cursor usually indicates a bad/corrupt file system. Too many hard shutdowns can cause this. I would connect the hard drive externally to another computer and run chkdsk /r on it and it maybe to fix it.

 

Hello im not to sure i think its nvidia
its exactly how it is on the link i porivided two cables go into computer

like i said it was all working fine until i took it apart put it all together black screen then it went blue (which was my login screen) then black
and if i press cntrl and alt delete on system startup to restart the pc the screen has a white blinking underscore then screen stays black so then thats where i put the external monitor on to see whats on screen?

i have also reinstalled a fresh windows xp now but still same problem no display on the laptop only external monitor