I had the same issue and another person I know who builds pcs had the same issue. No post. Beep codes were nothing like what was printed in troubleshooting section of manual. I decided mobo was defective and returned it. After two long weeks, my replacement should finally be here tomorrow. If this one doesn't work I will never buy gigabyte again. I think there is a large volume of these MB GIGABYTE GA-MA78GM-S2H 780G RT out there that are defective from what I have been reading.