Some mobos have a pre-check before starting. Some even have a two digit display with some codes that help diagnose during boot. That behavior is normal.
For the other issue, have you tried booting from a live cd or usb? A Hiren Boot CD or something similar?
When you say you ‘tested’ the components, you refer to swapping them with other parts or effectively testing (like Prime95, RAM testing, etc)?
Edit: yeah, re-read that bit, you say RAM is fine.
Perhaps you should check the BIOS settings, fresh w10 install (deleting all partitions) and driver installation. The only times I’ve had w10 act up were driver issues or bios settings.
