|"but all hardware are intact.."|
On what do you base this statement?
Have you tested all the components in your system to prove them in working order?
Troubleshooting a non-booting system has been described in detail in the General Hardware forum hundreds of times.
If you really want assistance here then describe in full detail what happens/doesn't happen when you try to boot. A full description of any testing you've done would also be useful.
Goin' Fishin' (Some day)