AsusPro P450C - No Bios Screen_Wont Boot_Dead

A friend gave me their AsusPro P450C laptop to fix.
OS: Windows 10 Pro

Problem: They were trying to create a USB balenaEtcher boot disk, and upon rebooting, NOTHING appears on the screen, not even the BIOS splash screen; totally dead.
Only the power light and the fan spins.
I tried booting a USB live disk (Win10, Linux Mint): nothing.
I replaced the CMOS battery: nothing.
I unplugged the laptop, removed the DC battery, drained the CMOS settings; nothing.

They stated that when they were creating the USB balenaEtcher disk, they selected the balenaEtcher.exe file, then a warning appeared stating that "this file does not contain a bootloader (or such)", and clicked OK, and finished creating the disk.
Then they entered BIOS into Boot order and put the USB balenaEtcher disk as the FIRST boot device, then rebooted.
Upon reboot; nothing, dead, kaputz.

I believe that the problem is that when they created the USB balenaEtcher disk, the balenaEtcher.exe file did not contain a bootloader, then they put the USB balenaEtcher disk as the first boot device in BIOS, so now when they inserted the USB disk, the PC does not boot because the USB balenaEtcher disk does not contain a bootloader, hence you cannot enter BIOS anymore to correct the problem.

Since the laptop is dead, I can't enter anything to change what he did.

If anyone has any suggestions (other than recycling or replacing the mobo), please let me know.
Thank you for your assistance.

 

I tried booting:
Laptop OFF.
Press F4 & hold.
Turn laptop ON.
Nothing.

I also tried pressing & holding F1, F2, F3, F4, F12m Esc, & Delete (all separately) then turning laptop ON.
Nothing.

All the above was tried with & without a USB flash drive containing the BIOS update file.

When turned ON, the power light comes on, the fan spins, the SSD light stays on for 4 seconds then goes out, the WiFi light stays on for 4 seconds goes out.