ps3 cech 3004 help need (tried to downgrade)

Hello
my friend try to downgrade ps3 cech 3004 with flasher and he lost original flash dump
so my question is is it possible to unbrick this console. if i dump again this flash and try to change it to original this parameters what he change for downgrade?
i know that is impossible to downgrade this console so i ask if i can reverse that error