well first i put it in dfu mode.
For that hold the home and sleep/wake button together exactly for 10 seconds and then let go of the sleep/wake button and keep holding the home button for another 10 seconds. I wasnt able to see anything on the screen coz it was black throughout so I timed myself using a watch.
After that the comp will detect you iphone in dfu mode (the screen will still be blank). I used ziphone then to erase BL 3.9 baseband option.
After that I did a restore from itunes and the phone came alive. If you are facing a similar problem and need any help, let me know. Would be happy to help.
