Can't open the partspicker...
It is an APU so keep it simple and don't install the GPU but connect your monitor to the display port on the motherboard back plate.
secondly double check connections... all of them. reseat (or just check) CPU and memory. reseat the 20+4 pin connector. reseat the 4+4 pin CPU power connector.
you might also reset CMOS before starting it up... disconnect power, pull the battery and short the pins for about 30 seconds. then reverse and power up.
have the new BIOS on a memory stick, extracted from the distibution file, named properly and ready to go. Insert in one of the backplate USB ports. When it boots spam...