phone does not boot when I reset all settings and content

hi,

i have a major problem, some days back i reset my phone with resetting all settings and content. mine is a phone with firmware of 3.0.0. i had also installed openssh and various other applications from cydia. i had also changed the root password as was advised while installing openssh. after i selected reset all settings and content, my phone is stuck in limbo. on starting it shows a apple logo and continues to show that till it suddenly disappers and screen goes blank and again starts but shows the logo for a long time then again goes dead and again starts and does the same till battery drains out. when i connect it to itunes it does not get detected my either itunes or computer.

please advise what to do?

if any tutorial is available kindly give the link.