I updated to 5.20 but how can i Downgrade to 3.52??

Depending on the PSP Model 1000-2000 you can downgrade your PSP using Custom firmware by forming a MMS using RainsUltralite and a Pandora's battery. Custom firmware equivalent to the official firmware can be determined by the games played. Most recent games require updated firmware. This site should help you with all the software necessary to downgrade or modify your PSP. http://pspslimhacks.com/rains-ultralite-mms-maker-for-500-m33-4/

You can only upgrade the firmware on the psp 3000, The 3000 at version 6.20 still hasn't had a hack to downgrade it.

if you have downloaded the firmware from the internet, that is really not advisable. it would be best to go the nearest gaming zone for updating firmware.
some firmware are not compatible and not updated. downgrade your firmware to a more stable firmware.

resore the default stuff, under system settings. Y do u want 2 downgrade tho???

hi your previous psp version is 3.80 m33 if yes your using custom firmware that why you can play game to your memory stick the problem is you upgrade your psp firmware to sony official firmware 5.01 you reinstall your firwmware again using custom firmware like 5.00 m33-3 cfw below with m33 or OE

Hi There Jawwad,

I have found an online tutorial that will walk you through each step of the process.
before the link. make sure that you Keep in mind that working with firmware is always risky. Having the power supply cut in the middle of a regular Sony authorized firmware upgrade could very quickly turn your Expensive PSP into an Expensive doorstop. Anything that goes wrong with this hacked downgrade won't be covered under warranty, so make sure you follow these steps carefully and in order, and consider yourself warned. Proceed at your own risk. Also, be careful where you grab your copy of the downgrader and the 1.5 updater used in this tips; there have been reports of malicious packages posing as these two items that can actually destroy your PSP.

Here is the link : http://sony-psp-tips-tricks.blogspot.com/2008/01/how-to-downgrade-psp-firmware.html

Hope this helps ?!

Hi davidjuarez1,

You can downgrade/upgrade the firmware of your PSP. Visit pinoypsp.com or check any website that can guide you on how to properly flash your firmware to fix issue. Frozen PSP is usually a firmware issue, upgrading/downgrading it solves the problem.

Thanks,
Marvin

It's impossible to downgrade your PSP from it's current version. I'm not quite sure why you'd want to downgrade, but maybe you should upgrade (If a version is available) again and see if you like that version better. ^-^

Hi,

The official Sony firmwares don't let you play downloaded/back up games.