I dissembled my Toshiba Satellite A135-S4527 to clean it on the inside, but once reassembled the screen stays black. It is visible that the computer powers on, but there is nothing on the screen. I pressed Fn key in a combo with F4 and F10 to no avail. Besides that I tried taking out the HDD and then putting it back after one minute and that did not fix it. I did one other thing - hooked up the external monitor and nothing even comes up on that other monitor too. In addition, I double checked all the connections and everything seems to be plugged in correctly. Video cable is plugged in also. Are there more than 1 video cables that connect to the motherboard? I also have a ground wire that runs short along the video cable, but I am not sure where that cable is supposed to attach to. I just leave it loose tucked in by the laptops hinges. I have pictures of all this, but I am not sure if I can attach them here. That would definitely help. My computer was working very sluggishly, but now I cannot use it at all.