Two ET6000 just stopped working.

The image freezed, turned off the machine and it did not boot at all after that. No leds at all. Totally dead.
Tested the power supply and no problem with that. Took another et6000 and used that instead couply of days. Then also the same with this unit. Now i have two units that stopped working.

Tried to insert a usb to reflash the machine but no success as it does not power up at all and no leds are visible.

Any ideas what it could be? Tested two different power supplies that i know works, but no success. It is something with the et6000 itself.