Question 12V and 5V power short - Motherboard dead?

[MuddyPuddles]

Hello everyone, I had probably quite a unique accident, and I kindly ask for your help on this. Here is the synopsis.

In my PC, the case fans are powered directly from PSU through a molex connector adapter, via Fan Speed switch, that seems to be switching its power between 12V (High speed) and 5V (Low speed).
Yesterday these 12V and 5V lines got SHORTED together inside of that switch (it is one of those crappy slide switches).

Fans obviously started to spin really fast, display went black and even though I immediately switched my PC off, there was already smell of burned electronics.

After that I disconnected all case fans and that faulty switch from everything, and here is what I got now:

• PC turns on
• CPU fan spins normally (it is connected to motherboard)
• there is no signal on display from both dedicated GPU card and from integrated GPU.
• LEDs on a keyboard do not light up
• EZ debug lights solid white for CPU
• I've tried to connect a system speaker to motherboard, but there is not a single beep from it after powering up

What I did:

• Checked PSU with a paper clip method, it works, measured voltages - they are good.
• Installed this PSU into another PC, it works, voltages in BIOS are good.
• Installed GPU into another PC, it seems to be working. There is an image on display, no malfunction LED on the card, its fans spin normally. It seems to be running quite hot, which concerns me, but tbh I've never touched it's radiator before, maybe it is normal.

So there obviously is a problem with CPU, so the Question is:
Is it safe, to try a new CPU on this motherboard that had an accident? Or could the motherboard got permanently damaged to the point, that it might somehow damage the new CPU if I try it in it?
Is it even possible for a motherboard to damage other components at all, after such an accident?
Is there a way to check if the motherboard got damaged at all? No beeps from a system speaker is concerning.
Or would it be a better and a safer solution to also buy a new motherboard?

It seems to me that when 12V and 5V lines got shorted together, everything received something around 17V, right? In that case pretty much EVERYTHING should be toasted, right? CPU, Motherboard and its chipset, RAM, SSD, everything? I was really surprised that GPU still works. Maybe there is a hope that SSD's survived as well.

Here are the specs, if it helps:
MSI Z490-A Pro
Intel i5 10600K
HyperX Fury DDR4
Asus Dual Series GeForce RTX2060
BeQuiet System Power 9 PSU

 

[SkyNetRising]

Is it safe, to try a new CPU on this motherboard that had an accident?

It's rather hard to kill cpu. It might be fine.

Or could the motherboard got permanently damaged to the point, that it might somehow damage the new CPU if I try it in it?
Is it even possible for a motherboard to damage other components at all, after such an accident?
Is there a way to check if the motherboard got damaged at all? No beeps from a system speaker is concerning.
Or would it be a better and a safer solution to also buy a new motherboard?

It's hard to predict consequences of such damage.
But I'm quite sure, motherboard replacement is necessary.

It seems to me that when 12V and 5V lines got shorted together, everything received something around 17V, right?
In that case pretty much EVERYTHING should be toasted, right? CPU, Motherboard and its chipset, RAM, SSD, everything? Maybe there is a hope that SSD's survived as well.

Shorting 12V and 5V, pushes 12V to components using 5V. Those would get fried.
Motherboard and sata drives are most likely candidates to die.