Originally posted by DX4EVER
But it happened after a update
A ps3 will only shut off, and stay off, for a few different reasons..
overheat
busted component
or
corrupt flash
You COULD try to install a new hdd and see if it wants to boot up.
If that doesn't work, you could try reflashing
If that doesn't work, you could try reflowing
If that doesn't work, the ps3 is done for from something fatal (broken), or will require an extreme repair.