Is it plausible that an interrupted Windows update can cause the motherboard to fail?

When I turn on my Windows 10 desktop (a Dell XPS 8920 Desktop), and after the latest Windows Update I get a black screen. There is no splash logo or anything - the screen is completely black at all times. When powered on the computer starts up, then I can hear after 17 seconds (I timed it) that it reboots, and the process repeats endlessly.

I've discovered that I can get into the BIOS screen if I press F12 as the computer's restarting. I can't see that I'm in BIOS because the screen stays black but it seems clear to me that I am, because I get predictable outcomes by pressing certain keys (e.g. If I press F10 to save and exit the BIOS, I can hear the computer make a restarting noise). However, restoring the BIOS to factory defaults doesn't fix anything.

After I called out a repairman in relation to the problem, the repairman has suggested to me that the problem was caused by a power outage during a Windows Update, which has then corrupted the motherboard, and that the solution is therefore to replace the motherboard.

The motherboard is being replaced at no charge to me as the machine is under warranty, so the claim isn't a self-interested one.

But still I wonder if this is plausible.

The power outage was caused by a tradesman turning off the power at the mains when the computer was being updated. I am also using a surge protected powerboard so I doubt that a power surge is the issue. I also have now seen that the computers fails a POST test even with the GPU replaced, and it also did not beep when the CMOS battery was removed and put back in place.

Update: After the motherboard was replaced the screen started working, although now the system does not seem to recognize Windows anymore. The current plan is that I'll be given a replacement SSD (as with all the service and parts so far, I'm not being charged for this) and instructed just to install Windows again.

Answer

(The answers given by others are, I think, wrong).

Although somewhat unlikely this is possible. Manufacturers can indeed get Windows to update firmware and UEFI during a Windows update, and if this process is interrupted you could indeed hose a motherboard.

See https://docs.microsoft.com/en-us/windows-hardware/drivers/install/updating-device-firmware-using-windows-update to read it "from the horses mouth"