cant switch on again

i cant switch on my beagleboneblack again.i tried a new hdmi adapter, then used the old one and it didnt show a picture on my tft. i pushed reset and on button . After that the leds didnt shine anymore and it also0 hasnt been recognized by my windows computer.
How can i start it again or is it broken?

pls answer.

Did you look on the support Wiki? The URL is on the white card that came in the box with the board.

Here is the HDMI debug page

However, you may not have gotten that far, which is what it sounds like. So, go to the support site and check the various topics and the FAQ. Gather more information form that. Then if you need to post a more detailed message as to what the sequence was that you tired, things like power source, monitor, version of the baord. Software image you are using.