Complete detail:

I have the iphone 3gs otb with 4-5 digit serial 41, with legal att sim.

I jailbreaked with blackra1n rc2 and got to main screen on iphone.

Than I opened the itune and did shift+restore and select the file a friend sent.

It took a long time at "Preparing iphone for restore and then it gave me 1604 error."

Meantime iphone went into recovery or dfu mode and only way I can get out is to do a restore from itune.