In need of assistance with fixing PSP firmware

First of all I would like to mention I'm kind of new to the whole PSP thing,
The problem is that a while ago, I tried upgrading the firmware on my PSP in order to play newer games on it, resulting in basically screwing it up.

Im not sure about what type it is, though I can answer it if you will direct me on where to look, but it basically is one of the old "fat" ones,

Now after trying to install the new firmware, when I try to turn on the PSP now , the screen remains black.

Is it possible to fix this kind of thing on my own with the proper instructions or should I just take it to a professional?

Thank you very much.