Are you using the IGP of the 8600G? Which motherboard port is the monitor connected to?
Is your memory 1x16 or 2x8? Have you verified the correct slots for your board?
What CPU cooler are you using? Is the fan connected to the header labeled CPU_FAN?
Check the thermal paste application. Ensure good coverage without excess on the CPU PCB or socket area.
Reseat the 20+4pin and 4+4pin (or 1x8) power connectors to the motherboard.
Try a different power outlet or connect a power supply tester.
Ryzen R7 5700X | B550 Gaming X | 2x16GB G.Skill 3600 | Radeon RX 7900XT
Ryzen R7 5700G | B550 Gaming X | 2x8GB G.Skill 4000 | Radeon Vega 8 IGP
Ryzen R5 5600 | B550 Gaming Edge | 4x8GB G.Skill 3600 | Radeon RX 6800XT