Mine also crashed in the same manner

Now
When you turn it on it just shows Sony for a second and then NADA

I have not idea what else can I try

how do you enter the menu for a factory reset ??

is there a way to avoid automatic updates?
i keep seeing my version went from rel 7 to rel 11 without my confirmation..

i love they constantly update, but im afraid in some update the power will fail while updating,

also i think i cant root anymore in REL11 so i want to stay in rel11 in the event ...