Default [Q] [q] xperia p wont power on !!

My Xperia P is not powering on.
Yesterday i was installing custom kernel on it. But I missed one important point in the flashing of the cyanogenmod kernel, and ended with a BOOT lOOP. So i removed the battery in order for not to wait for several hours to let the battery die.
Then i fastbooted the phone and flashed stock firmware using Flashtool. The only problem is that now it wont power on. No display. NO vibration. NO hard reset thing. NO soft reset. The device is not responding at all. If I connect it to the PC or wall outlet, red led comes, and after 5 mins or so, it goes off.
I thought i messed up with the kernel or so, so I with the help of rubber band trick, manged to get into flash mode, and re flashed the system with the stock rom.
But AGAIN IT WONT POWER On ! no matter how long i press the pOWer ON key, it wont respond.
what should i do now ?? please help me.. !