Screen with interleaved black lines

Hi,

I opened my Kindle 3 to try and fix the reboot problem (very frequent random reboots) by finding something that short-circuits my battery. Problem isn't fixed, still exists, but I must have moved or touched something related to the screen controller. The whole screen is now overlaid with perfectly regular horizontal black lines with a spacing of maybe 0.5 mm.

Is this a known problem, and what did I do / can I fix this?