Default Changed DPI => Blinking Screen

Hey there

Recently updated my touchpad from old 4.0.4 android to CM11 4.4 Kitkat

I wanted to get lower dpi, used lcd density modder or smt like that, reboot, chose android, but now the screen is blinking on (black) and off.

Tried keeping the power button pushed but it doesn't shut down, tried plugin into pc, I hear the sound as if a device is detected, but it doesn't appear

Any idea beside waiting for battery to drain ?

Is there any (not too old) rom with dpi option in its parameters ?
_
Thanks

Edit : Power + Home did the trick