Your thread title says it all. Unfortunately your PSP has become "bricked" due to the PSP shutting down while in the middle of writing the new firmware to the components inside. This is why Sony says to have the ac adapter/ charger plugged in to the PSP every time you do a firmware update.
The only thing that you ca do now is contact Sony and ask them about repair/ replacement of the PSP. If it is under a year old and you have the receipt you will be covered under warranty and this will be done at no charge.
As for your other post, it did work- the Customer Service area is set up to have new threads be invisible until approved by a staff member (we occasionally get some spammers in there so it avoids them being seen by everyone).