[geekmaster]

If the screen is damaged, you can temporarily connect the screen from your new kindle to it by taking off the back cover. You need to be careful to not damage the display cable when opening the back because it is right at the edge -- do not use a sharp knife to open it. Sharp plastic (such as a guitar pick or a credit card with a sharpened corner is much better).

With the cables at the edge, you can fit the kindles together such that you can borrow the other display without removing it. This is how I activated the voice guide on one of mine, so it was usable without a display. Both kindles had different menu items enabled, so I could not navigate the menus blind by comparing them.

Even without a working screen, it is useful for development using SSH. You can test the screen by plugging it into the good kindle. That should determine whether the problem is with the screen or the kindle hardware (or firmware/configuration).