T-Mobile Mytouch 3g was working and fully charged until it turned off and won't turn back on

[xilysherri]

T-Mobile Mytouch 3g was working and fully charged until it turned off and won't turn back on?
I tried taking out the battery, Sim & SD card and restarting it, still doesn't turn on... I even tried plugging it to a charger. I even tried using my friends Mytouch 3g battery to put in mine, and still no luck Please help, thanks!
I really love this Phone