nbox 5800sx stuck

Hi all, got a problem with my box, i turned it on today and i am getting nowhere with it. i had it loaded and working properly, not too sure how this has happened. when i turn it on i dont get the usual messages on start up, b4-u-[ b4team ]- after that i get usb update or custom boot 1. nothing else happens, ive tried loading duo multi boot using the usb update option and get nothing, just seems to freeze and the same goes for custom boot 1. does anyone have any words of wisdom it would be much apprecitated. thanks