has anyone got a 640 was wondering did their SD card click into place or just push in as it doesnt spring in or out and also do you have a visible light under the windows logo?
Are you asking about a backlight for the 3 touch buttons (back, start (windows logo), search)?
If so, these are software buttons on the 640 which are incorporated into the screen. They aren't separate capacitive buttons such as those on the Lumia 520, 830...etc. Therefore, a backlight is not required, as the buttons are shown on the screen itself.