I am sure I am missing something obvious, but after removing the write protection screw on the motherboard i am still getting the response write protection enabled. I only have 3 screws on my motherboard. 2 silver/brass retaining screws and one painted black large headed screw which I have removed. I have also removed power from the board thinking it needed to be reset but this had no effect. I cannot find any information about the board to find out if there is a reset button or something else needed. acer chromebook 15 cb3-531. just trying to create an ubuntu only laptop to learn linux on. tried the crouton option and it is nearly unusable having difficulties with supplied web browser while in linux keeps hanging on most sites.