Aurora R16, only GPU light and back fan on, won't power up

Husband has his PC on, went to take a nap, came back and it was off with only the GPU light on and the back fan. It was not put into sleep mode. Cleaned the dust bunnies he had on it, cleaned the plugs and changed the power strip thinking the problem started there. His keyboard and mouse wont light up. have tried rebooting it a few times, nothing. Any ideas I can try would be appreciated. I chose not to do anymore than that because it was 2 am, TIA