Originally Posted by boozr
The root password given by that web page is your ORIGINAL password for your main partition, based on your serial number, as stored in your main partition. The password for the diags partition is usually "mario" (without the quotes).
When you debrick by writing a copy of a partition image from a DIFFERENT kindle, your root password changes. We have a custom of using a password of "mario" (without the quotes) on debricking images for the main partition. However, there were some firmware images in the wild with different passwords, as documented in the posts where you downloaded them (or in a README file that came with the firmware).
Try the mario password...