(adsbygoogle = window.adsbygoogle || []).push({}); I wasn't sure where to put this thread so I put it here.
This was tested with a cex CECHG01, on rebug 3.55.2, which is NOT a backwards compatible model. I tested the games: Ratchet and Clank, Ratchet and Clank Going Commando, Jak II, and ATV Quad Power Racers. Some games worked perfectly and others didn't. You can't save with it. I am not responsible if this bricks your console since I can only confirm this working on mine.

Video for non believers. I did fast forward through the part where it installs otherwise the video would have been around 3 minutes longer.

1.So first off you you will need to download mediafire.com/?ntuflcu7s78z769
2.Extract it.
3. Download ps3devwiki.com/files/firmware/OFW-CEX/2.50/PS3UPDAT.PUP (download will automatically start)
4.Install the FactoryServiceMode.gnpdrm pkg.
5.Run it and you should enter FactoryServiceMode (I've been told that slims will brick in Factory/Service Mode but I've never tested it)
6.Place the Lv2diag.self (NOT THE lv2diag1.self) and the PS3UPDATE.PUP on the root of your flash drive.
7.Turn off your ps3 and turn it on with the flash drive in the usb port on the right. It should install the 2.50 ofw. If the screen doesn't come don't panic and just wait for the ps3 to turn off by itself (mine did this and it still installed it) Take out the flash drive after it's done.
8. Turn on the ps3 and you should still be in Factory Service Mode and ofw 2.50 and if you aren't you did something wrong.
9. Go to system settings and turn off the disc auto start.
10. Put in a ps2 disc and go to it in the xmb and start it. It should play now. Once again not all games work in fact alot of them are glichy. The only way to exit is to turn off the ps3.
11. To exit FactoryServiceMode rename the lv2diag1.self to lv2diag.self and place it in the root of the usb drive. Delete the PS3UPDATE on the root of the flash drive.
12. Turn off the ps3. Plug in the usb drive to the ps3 and wait for the ps3 to restart itself and you will be out of FactoryServiceMode.
13. Update back to the OFW/CFW you want.

Buy a cobra dongle or wait as these features are getting worked on the new cfw

Straight copy and paste from You must login or register to view this content. at least post the source url or something.

Thanks but don't wanna risk a brick.
Also all data will be gone you can mayby backup but mayby some data will get corrupted.

This is a good post but should have posted the url.