The child dropped the system unit.

Gentlemen of all with the upcoming NG! Help with advice on what to sin and how to find out what has taken a sip. Small piled up the system unit on the floor from a stand at a height of about 15-20 cm from the floor. After this incident, the computer stopped turning on. When turned on, no boot occurs, the monitor does not turn on, the speaker does not beep. At the same time, all coolers are working (percent, video card, exhaust hoods on the case), the backlight on the motherboard and on the video is on, the HDD also shows signs of life. From USB devices, the mouse and keyboard do not show signs of life (except for a barely noticeable single blinking of the keyboard backlight), the backlight on the headphones lights up. Visual inspection did not reveal any jambs. Tell me what it looks like?