text on half of display, graphics other half

The Kindle Paperwhite screen uses e-ink which will keep displaying the last image it was changed to even if the device runs out of power or if the display is disconnected from the rest of the device. Power and input from the paperwhite's processor is only needed to change what is displayed. It is possible that your display is damaged and only part of it is now receiving new information from the processor. This is likely if one part of your display keeps a fixed image while the rest of the display updates to a new page, but it is hard to determine this from your short description of the problem. If you have not already done so try a standard reset. Press and hold the power button on the bottom of your Kindle for 20 to 30 seconds. This will reboot the operating system. Give the device time to work. A reset may take several minutes. For more information about the standard reset and trying a factory default reset, read through this list. If you think you have damaged something internal you may find more troubleshooting help here.