why cant i get 'Marathon man' achievment for halo 3 on xbox 360?

[HonourTAG]

i've found all seven activated them (even the extra one on cortana), and have waited without pressing any of the buttons to skip the writing and i still won't get the achievment. why?

 

[OPTICS]

Order does not matter, nor do you have to finish the whole level, you do however have to start from the beginning of the level. Also when you finish scanning the terminals last page, wait til it turns red and then another set of pages will pop up, just scan through those , wait a few secs just in case and then exit the terminal.

 

[ternot2007]

Only press the B button when the red arrow appears at the bottom.

If you pressed A, it probably wouldn't work.

 

[B-rad]

you access the terminal then skip til the end until it flashes red then does that skipping bit, then you skip til the end again. you will see the green arrow ^ turn red <

P.S not sure if it has to be in order

 

[Hardcore Gamer]

I believe you have to get them in order and make sure that you do read it all. Most if not all of them have this long pause in the middle of them and than it scrolls into a random direction for more content.

Note: That you literally don't have to 'read' it, but rather just wait at least.