Your question was answered only 4 posts ago by stock2255.
You can still upgrade with a broken drive/lens but not a broken logic board for the drive or broken ribbon cable to the drive. This lets you get round that problem.
I'm pretty sure it's for any level of downgrading 3.55 or below.
What would be great is if us poor buggers who don't have the correct blu-ray drive could use CFW.
Anybody care to share why this corrupted my FW, then it had to wipe my hard drive?
I installed using my TI-84+ as a jig.
However, I manually turned off the system after loading the first Lv2diag.self. I figured it was expecting me to, since it wasn't doing anything but sitting there.
Just great.... All my data...gone....OMG.
I guess it's my fault....
I hate Sony now... Why did they wipe everything when installing the update.. It didn't even warn me it was going to do that... God dang it.
Edit: Don't worry, I don't get mad at people, ever. Feel free to say something...
Sounds like it is good progress in the scene.
This saved one of my old fat ps3 with 256mb nand from a update that went wrong because of the bluray drive being stuffed. So thank you very much JaicraB, keep up the good work. ;)
For 3.55 don't you need a custom pup that has a version string changed to 3.56 or something? I thought they released a pup or something that had a modded string so you could downgrade 3.55. Which is probably why it's not working. You need that pup.
Certain PS3's have their data wiped. It's a part of the process. So it's an intended feature. Nothing the developers can do about it. It has to do with part of the firmware being on the HDD. So it get's wiped in the process. Again intended feature it was done correctly.
Also to everyone somehow confused about the first post (don't know why you would be but whatever.) this lv2.diag is for people with completely broken blue rays including logic board, ribbon, or something in conjunction with the BD where you can't update even with official firmware. It also allows people with perfectly intact BD players to keep BD-playback after downgrade which was a problem with previous lv2.diags.
Also I believe 3.55 downgrading requires a custom pup that has a modified version string. If I am wrong someone can correct me but I believe I read that in the 3.55 downgrading original thread.
EDIT: Yup 3.55 downgrading requires a modified 3.41 pup that has info0 replaced with 356. So basically it's a 3.41 pup modified to look like a 3.56 firmware so you can then go down.
Taken from here : this thread/post : http://psx-scene.com/forums/675352-post241.html But again make sure it's the right firmware. It is modified 3.41 to look like 3.56 it is not the real latest firmware.
Hey can someone make a tut on this with the tools and where or how to get them. Thanks in advance