this has recently happened to me by learning the hard way, i tried to install firmware in factory mode prior to reading instructions before attempting oh dear, major learning for me here.
At the moment whenever I switch on the ps3 it comes up installing update 0% after a second or 2 red screen comes up with serious issue in a 100 languages.
I can't find a solution to this, tried with dongle, trying service mode everything but just gets to the red screen. Still under warranty but not sure if they will know i had homebrew apps.
If anyone has any advice would be greatly appreciated.