If the "it" is a TV then it may need repair. You can try unplugging it from the AC for 5 minutes to try to reset it.
Contact the manufacturer as the blinking light may convey some information on the problem by the number of blinks.
New, or old setup?
If new, try testing the board outside the case. Make sure that the CPU power cable is connected to he motherboard. Disconnect all case fans when testing.
If the "it" is a TV then it may need repair. You can try unplugging it from the AC for 5 minutes to try to reset it.
Contact the manufacturer as the blinking light may convey some information on the problem by the number of blinks.