Which type of screws are in the back cover of this laptop?

Hi

The hardware maintenence manual for the laptop, taken from this support webpage doesn't specify the type of screwhead securing the back cover, only the size and number of screws . See p.33 of the manual.

Post an image of the screwhead in your question which may help to identify the type of driver required e.g. Torx , Security torx or Philips head etc. Here's how to do this on ifixit iFixitでの質問に画像を追加する方法

hi,

It looks like a torx screw so measure the distance between and two of the point i.e. diagonally to find out approx what size torx screwdriver you need.

Here's an image showing the sizes

(click on image to enlarge)

ifixit sells a range of torx drivers one of which may be suitable