I tried to downgrade my Ps3 from 3.5 using the guide here, Simple Tutorial on How to Downgrade and Jailbreak your PS3 with PsfServiceMod (PsfMod) « ****ed up in the Head

I got up to step 22 where the green light was just flashing and nothing else was happening.

Then i turned the PS3 off to try again, but now when i switch it on, after 5 seconds its goes back off again.

Any idea on how to fix it?