Just bought a PSP, firmware 3.40. Can I downgrade it?

Subject says it all.

Yes u can downgrade it with the 3.5 downgrade but u need to have a copy of the UMD lumines .

Upgrade to 3.50, and use this tut:
http://boardsus.playstation.com/playsta ... id=3020586

Thanks for the lightning fast replie. I will do what you suggested.

Anytime, but just be sure to update to 3.50 and then downgrade, and watch out for any warnings in the tut I sent.

Where can I find a 3.50 upgrade? I got to third step in that tut, but the screen turned red, and the PSP turned off and didnt restart. Im thinking I need to upgrade to 3.50 first. Thanks in advance.

[ace]

Well it is a 3.50 downgrader. You can't downgrade a different firmware then the one the downgrader is made for.
http://www.pspbrew.com/?page=fileInfo&cid=5296&d=5009

your screen went red and didnt restart? so are you saying that you cant turn it back on now? cause in the past when you get that red screen it usually means you bricked your psp.

Anyways if your psp still works fine...Do not use the tutorial mailas provided, it is very vague for beginners and lacks crucial steps.

Use the one that ace provided you, its way easier to follow.

where is the one ace provided?

here... http://www.pspbrew.com/forum/viewtopic.php?t=8427