Have you any news about the problem in your phone?
Mine (i8190 with one of the mclaws roms from previous week) also appeared in the morning shut down and there's no way of starting it. It does not even vibrate when power button pressed, as if the battery was completely empty.
Tried with another battery and checked that the original one had charge, but no luck. It does not start (normal, download or recovery, makes no difference).
Any ideas?
I had an similair problem like you. My phone died suddenly and nothing worked and if I say nothing I mean nothing, like you. I send it back and they changed the mainboard and the battery. I knew it was flashed with CM, but they werent able to find out So at least try it ;D