Problem downgrading DIA-002

Hello, I'm trying to downgrade my PS3 with firmware 4.0 but using the norway I get this:

Pinging...
Set SB to tristate

NOR chip manufacturer: unknown (0xfe)
NOR chip type: unknown (0xfefefe)

STATUS_TRIST_N: True
STATUS_RESET_N: True
STATUS_READY: True
STATUS_CE_N: False
STATUS_WE_N: True
STATUS_OE_N: True

Resetting NOR...
Ready.

And the backup nor just gives me only FF or FE values. Any ideas?

Sorry for me bad english.