Not sure you quite understand, the mobo doesn't post for 20 minutes, like the screen is black and power direct go into the keyboard and mouse. The computer for all intents and purposes is off waiting for the mobo to engage.

Did you try the car audio sub?

Try unplugging every unnecessary peripheral and booting and see if that makes a difference.

Have you been watching your boot LEDs?
I asked about the memory because you could have a faulty ram stick, or not seated properly, if the LEDs get to DRAM and then stop/restart it could be that

https://download.msi.com/archive/mnu_exe/mb/E7C94v1.2.pdf

Refer to page 40 for cmos/bios reset
Page 43 for boot LEDs
Page 45 for UEFI/CSM boot modes
Page 46 for flashing

It seems like you’ll need to dig into the bios debug/flash troubleshooting

You can always troubleshoot with MSI tech support, one thing I’ve learned is most companies actually have a decent tech line as to avoid rmas

+1 here

Your sdd / hdd can be broken

download CrystalDiskInfo and check if everything is okay.

and one thing you can do is remove battery from mobo and let it be 10min off and reinstall battery to mobo. (this will reset your mobo settings)

can you get sdd somewhere and isntall win 10 in there if its broken hard disk.

E: and check in bios your launch priority.

This post was edited by rapsu on Jul 9 2021 12:36pm