Default Need Help

Hello.
I have a samsung galaxy s2 and its been working fine for more than a year. Few days ago, i did a factory reset and now when I power on my phone it stays on the Samsung logo. If i go in recovery, it says CWM-based Recovery v6.0.1.2-Siyah. and i have a lot of options. I did wipe data/factory reset and after that completes it powers on and goes in safe mode, i can do stuff for around 30 seconds and then it restarts and stuck on samsung logo again.
I tried flashing stock firmware but Odin does not detect my phone. i have tried on two different computers, they both have the drivers everything, tried on different ports, tried with different cables.
Please Help.