passero
Seems that your reader is bricked. Have you use "bigit"'s custom firmware before? Did you have many files in internal memory?
To unbrick it, you'll have to do 10 timely resets in a row, i.e. do it right after you see the startup screen 10+ times. After it, reader will fall into firmware update mode. Then just use standard Sony's flasher (or use this one
http://projects.mobileread.com/reade...%20Special.exe it doesn't matter). This will get you standard 1.1.00.18040 US version.
After that, you could try PRS+ installer again.