I have a black Kindle non touch. I have successfully jailbroken the device using the guide on mobileread's wiki and right now I'm trying to get custom screensavers to work using this thread
https://www.mobileread.com/forums/showthread.php?t=88004. I have both the Python package and the kindle-ss-0.33.N.zip part installed, or at least I think so. The proper folders are created in my root folder of the kindle during the update process along with a Python folder. I have put a couple of 600x800 png/jpg images in the screensavers folder inside linkss and have made a reboot empty file to reboot after i disconnect the Kindle from USB. Once the Kindle starts back up, I try to put it to sleep, but the screensavers that I have put on there still do not appear. Am I missing some steps?