LG L90 accidentally I changed the "bootloader"

I have a LG L90 and accidentally I changed the "bootloader"; but now I can not turn, I can not even access the "S \ W Update" mode.

I have the file ".kdz" but nothing yet, because I've put volume + and connect the USB cable to the PC, and nothing.

Some help me.

I remove the battery and connect the power charger or PC and show me on the screen a cable with a battery and an exclamation point. If I put the battery is not detected on the PC.