The Spanish PlayStation 3 developer dospiedras1973 who recently revealed both the PS3 Firmware 3.6x Downgrade via Infectus and PS3 3.7x Downgrade for Slims and Fats with NOR Flash has discovered what he believes may be a new PS3 METLDR revision in a CECH-2504 console (shipped with 3.60 Firmware) that blocks downgrading.

Below are his findings, roughly translated: New revision of blocks metldr downgrade for that guys, I found a console factory cech2504 with fw 3.60 and I found this:

Code:
00 00 00 01 00 00 00 01 00 00 00 00 00 02 E8 00 00 00 00 00 00 00 00 40 00 00 00 00 00 00 F9 20 6D 65 74 6C 64 72 2E 32 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00 00
Code:
..............�........@......�ldr.2........................

The console in question was a cech2504 with Datecode 1B. I guess that's where that will forward all Datecode and not downgrade for the moment.


Source- ps3news