yeah i would take it all apart again and make sure all the connecters are pluged it, expecially the cpu fan and video cable
i would double check everything before turning it back on. damage could already be done though
laptop works great otherwise, it reconizes when the ac is removed and dims abit but just the screen isnt bright.
if you through the settings and pick the brightness in the bios... it get brigher up until 6 or 7 then its darker after that..