dell inspiron 3521 i change keyboard while he was on, only power light turns on, the fan off and screen off

hello, i had a problem in my keyboard in my laptop dell inspiron 3521, so i tried it to reseat it and i forget that he is on, when i remove it, i smell a little bit a smell like a component was damaged, but i'm not sure about that, maybe this smell because it's the first time i opened the keyboard. So i reseat that keyboard and i see that my laptop tunned off alone. please i need help what i should do, i did bios reseat with holding power button for 3 minutes while i removed batterie and charger, and i reset the bios complettly with reseating the pill inside the laptop, and i did reseat of the component also.

please help me and thanks you