ATV no led activity, no DFU

I had succefully jalbreak my atv with seas0npass 0.6.5, everything seems to be fine, excecpt no wifi and no network. I unplugged power cord and plug micro-usb to jailbreak it again with 0.6.6 (seems to solve the problem), when i plug usb cable, i have no led activity, try menu/play, and menu/down + menu/play and no flashing led (more then 25 times). Then i plugged the power cord and there is activity, try menu/down, and menu/down + menu/play but no DFU mode, itunes and seas0npass do not recognize my atv. It could be from the cable or itunes but i have other atv with ios not jailbreaked and itunes recognize it.

Need help.

Thanks