My laptop won't continue to boot

I recently replaced the power board with its flex, first it turned on then disconnected it from the power and it wont continue to boot again..

when i press the power button, the light turns on, the fan starts. and after a few seconds, everything stops.

I observed that there is something very hot in my motherboard when the fan starts.

the circled IC is hot.

here is the IC close up

please help me and tell me the problem please