Default Underclok + creah problem

Hi, i've installed the cynogenmod 11 (4.4.2) with NakyakKernel.
After a underclok to 1024 Ghz (the telefone was HOT) the system crashed. The screen was black with the led bar red. I've tryed for a hard reset but that doesn't work. Then I've let the phone drain the battery and then recharg but that doesn't work.
This is my first tread.
-Marco