Originally Posted by Castleview
All the posts i can find say that even a PSP-1004 WILL NOT work, so you'd be stuck. I'm glad FaxiY asked if it was a 1001 model before you did anything at least.
The N900 SHOULD work but, again, do your reading first...I can't link to the relevant files for 'Jig Mode' for your N900 but you should be able to google them easy enough.
This is a link where N900 owners have used it to enter/exit Factory Service.
Hope this helps.
EDIT: If I were you i would just buy an E3 dongle if you're not 100% sure things will work. Digitopz sell them cheaply enough, i got my E3 Flasher there.
It should work on a PSP-1004. the 04 is the region, just like with PS3s.
So a PSP-1001 is the same as a PSP-1004. They are just from different regions.
Just like a CECH-2001A is the same as a CECH-2004A. Just from different countries.