Ensure the24-pin ATX and8/4-pin CPU power connectors are firmly plugged into the motherboard. If your CPU has onboard video, remove the discrete GPU and display from the motherboard's video outputs to rule out GPU issues.
MSI MAG B560M MORTAR WIFI LGA 1200 Intel B560 Micro ATX Intel Motherboard
MSI MAG B650M MORTAR WiFi AM5 MicroATX AMD Motherboard
MSI MAG B760M MORTAR WIFI II LGA 1700 Intel B760 SATA 6Gb/s Micro ATX DDR5 | New
MSI MAG B460M Mortar mATX Motherboard LGA1200 10th Gen Intel i9-10900K i7-10700K
MSI MAG B760M MORTAR WiFi AM5 MicroATX AMD Motherboard
