The blinking lights off and on for months

The blinking lights off and on for months

Mine has been the blinking lights off and on for months and it worked if I unplugged it and waited for a few minutes and started over .... went to Best Buy asked them what the problem was they told me around 2007 models there is a defect with the motherboard. So now I am trying to find out how to replace the motherboard....all the videos I see say they are replacing the HDMI board.... I need to replace the main one. Any ideas?

ANSWERS: