Sorry to hear about your other PSP.
Anyhoo, If you have a motherboard below TA-082 (See link below)
Then you just need these two. Appropriate instructions in the threads you download them from/readmes
Homebrew Enabler (Required to run downgrader)
If, however, you have a TA-082 PSP, then I believe your best bet is this. You'll have to update to 2.80 for this one.
With either of these downgraders, you'll need a 1.50 firmware EBOOT. You could get that from http://dl.qj.net/dl.php?fid=163
If there's anything else you need that I've forgotten, feel free to yell at me via PM or in this thread if ya need more help. ^^