Unhappy Help with my Sony Xperia J won't turn on

My xperia J won't turn on! I installed a rom, ALL OK, but SIM Card dont apear and I just removed the battery and put again the card.
When I turned on, it just wont work..I press the power button and it just flash 1 time the green LED and vibrate but it still dead.
If I continue pressing the power button it do this process every 1 or 2seconds.

HELP