Downgrade 3.71M33 without Pandoras Batt!

[roe-ur-boat]

This post will guide you through downgrading to 1.50 from 3.71M33 without Pandoras Battery. Follow the instructions to a tee and everything will go fine.

1. Go to recovery mode by holding R when rebooting your PSP. Go to configuration and set the GAME folder kernel to 3.71.

2. Download this file 3809

3. Now download this file HERE (http://72.29.74.204/~exophase/external/150.PBP)

4. Rename it to UPDATE.PBP and put it in the UPDATE folder you downloaded first.

5. Put the UPDATE folder in X:/PSP/GAME/ with X: being your PSP

6. Run the program on your PSP.

7. You will be downgraded to 1.50!

If you have any comments or problems just post below and I'll be glad to help.

[Darkchild]

just remember to run the GAME folder WITHOUT the 1.50 kernel AND do fully restart the PSP BEFORE you downgrade!

btw, thanx for the help roe, +rep!

[donsammy]

nice thnxxxxxxx

[roe-ur-boat]

alright cool, I didn't have to do that but I'll add it in anyways.

[V0dka_88]

I'd upgrade My psp from 3.40 OE to 3.71 M33 everthing went smooth until i changed to backup my flash 0. i back up it to changed my themes, first try my psp wa freeze so i copy back my back up flash 0. But my psp still freeze and now it went blank. I still could log into recovery. I dont have pandora batt or magic memory stick. how could i got back to 3.71 M33 or must i first downgrade to 1.50?? plz help me

[roe-ur-boat]

Firstly, you must have upgraded from 3.52M33-4 to 3.71M33 as it's not possible to upgrade from another. Secondly, go to recovery and Toggle USB. Place the 3.71 downgrader files at X:/PSP/GAME/RECOVERY instead of X:/PSP/GAME/UPDATE. Once you've done that, go to Run program at /PSP/GAME/RECOVERY/EBOOT.PBP. It should start the downgrade process. Once done, take the steps to update to 3.71M33

[dennis96411]

It won't work on my PSP when renaming it to RECOVERY and ran it under recovery menu. But it worked fine if I ran it in xmb.
Why? This is weird.

[roe-ur-boat]

Perhaps then, that cannot work. I would recommend x3's guide HERE (http://forums.exophase.com/showthread.php?t=1508) to downgrade a bricked PSP

[x3sphere]

It won't work on my PSP when renaming it to RECOVERY and ran it under recovery menu. But it worked fine if I ran it in xmb.
Why? This is weird.

It needs to be run under 3.X kernel I believe.

[frosty5689]

I'm assuming he put 3.40 custom theme files in flash0 and somehow the backup wasn't everything because of hidden folders.(some xmb icon files are hidden)

[pyrectic]

now for the stupid n00b question...

how do i enter the recovery mode? i've pressed&hold R during the boot up and i still can't get in

pliz help..... :crying:

[Acerthief]

Recovery Menu doesn't exsist in Official Firmware.

BUT, if you're on custom firmware, then the recovery.prx is probably corrupted.