S5 won't boot (Not even in any recover mode)

[AC Question]

Hi. After I flash my samsung s5 with a new rom, and after a full battery discharge the phone won't turn back on again.

Tried a new battery, so result.
VolUP+Menu+Power don't boot to custom recovery
VolDOWN+Menu+Power don't boot to download mode

I don't know what else I can do. Is the mainboard dead? Coincidence it happened after a new rom flash?

Help me please

 

[maclancer]

Does the ROM that you flashed on a custom one or a factory ROM?