Just to let you know I did it.
- I had to run the version that isn't lite.
- After a few attempts to see the file under the photo menu it worked.
- Went into red screen and then it blanked out.
- Turned on the PSP. Got the blue screen.
- Press O.
- And voila, my pal now has 1.50!!
His older brother messed it up a long time ago. When he first got it, it was a 2.0. I downdated it for him to 1.50 and only enjoyed a few days with it, when his older brother (not knowing) updated it to 2.70--because it wouldn't get the internet (his brother has one also and he keeps up to date with the updates... that fool!) So he was waiting FOREVER for them to come out with the downgrader from 2.70.
What I did was had to update it to 2.71 and then do the downgrader like what is available at psp-hacks.com.
One word of caution... since I had to open it up also to clean his screen since it was dusty as hell--had had almost give up hope with his PSP.. the little black screws on the PSP to take off the cover... man! They are sometimes very hard to unscrew! One that is behind the analog stick, I had to break it off and then replace it with another screw. But damn! If it ain't screwed correctly, the analog stick will get out of whack!
SO BE CAREFUL!!