PLEASE HELP my brother is building his gaming PC for the first time. His specs were 8GB of ripjaws ram, AMD athelon processor, radion 7770 core edition and a Bio Star Hi-Fi A85w. Also 1TB WD cavair black. After we put the PC together all the fans would spin up but no signal would come up on the moniter. The motherboard then said A3( legacy boot event). 3 hours later we have tried everything but no progress. We tried starting it without the graphics card, the we redid all the sata cables, then we checked and triple checked all the wires, we the redid all the front panel connectors and make sure they were perfect, then we unplugged everything and replugged it back in, and then we restarted the CMOS and still at A3. Please help straight away for we need this computer finished as quick as possible