There can be a few potential causes of the "MSI motherboard not booting" issue including missing power supply cables, incorrectly placed RAM, missing motherboard standoffs, overheating of the CPU, etc.
It would be quite difficult to fix all of these problems on your own, so I advise visiting an MSI Repair Service Center so that all of these basic to complicated internal conflicts with your MSI motherboard can be addressed correctly without worrying about causing further harm.
