[dlbogdan]

So you, like myself, were one of the first to go DEX following a very long linux guide? You, like myself, weren't instructed to QA flag your console before doing that.
Now you want to go back to CEX to try the new custom firmware goodies.

Say Bye-Bye to your PS3 Data. I never cared anyway, I don't really use my PS3 for gaming.

Right, so here is how I've done it:

I've first started by following this:
http://www.ps3crunch.net/forum/threa...-No-Brick-Risk

but there is a tiny bit of information missing ( very important one )

So, to review the steps:

1. downgrade from whatever DEX fw you are running to 3.55 using the downgrade PUP.
2. update to OFW 3.55 DEX PUP.
3. update to Rogero 3.55 V2 DEX !!!!!!!! (We need peek and poke)
4. put on a flash drive your original CEX dump and rename it my.CEX.EID0.NORBIN
5. install mmCM_ver_04.06.02_BASEPLUS_(20121002) (might work with other versions but this is what I've used, it has to be CEX version)
6. download rogero cfw 3.55 3.7a (CEX) and put the PS3UPDAT.PUP on the root of the flash drive
7. download the big lv2diag.self (365kb) and put it side by side with rogero cfw on the root of the usb drive.
8. download and install FactoryServiceMod.pkg (don't run yet)
9. with the flash drive in PS3 (I've always used the right port) start multiman and mmOS, go to the flash usb and click on the my.CEX.EID0.NORBIN. accept everything and wait.
10. exit to XMB and run factory service mode
11. if this takes just a few seconds something is not right, search for a file named factory.txt and in it you must not find any error. normally this should take about 5 minutes and shut down your ps3 by itself (Don't manually turn off your PS3)
11b. If you do have any error in factory.txt and don't you dare turn off that PS3! I had an error (because I've tried all this using 3.55 OFW instead of a peek and poke enabled one) and I've just wrote the DEX flash with multiman again and investigated a bit more. You might want to also check for a file named : UPDATER_LOG.TXT (witch should be a long file with a success tag at the end)

12. if everything is green, with the PS3 turned off, replace the big lv2diag.self with the small (4kb) lv2diag.self and turn on the machine on with the flash drive inserted (right port as always).
13. in my case the ps3 just turned on in service mode but another power cycle did it and the PS3 started with the CEX firmware Rogero 3.7a (with patched LV1 for checks)
14. follow this guide to properly dehash : http://www.tortuga-cove.com/forums/viewtopic.php?t=3638
15. now that you are running good ol' kmeaw 3.55 you are ready to explore the new kids on the block (like 4.21 CFW)

Cheers!