After the PC freezes, the mother began to whistle and performance dropped, what could be the breakdown?

Question

Iron

I watched YouTube, nothing lagged, the computer abruptly hung on the mouse and did not react, then the picture disappeared on the monitor. On pressing the scrollock (on the keyboard, the backlight turns on), the light turned on after 3-5 seconds, I had to turn it off by pressing the power button, turned it on - it seems to work. And here I launch a game in which there were 60fps and it gives out 4, in CS source it was 300, it became 20, and the motherboard started to whistle before this was not. Everything is fine in Windows, everything opens as quickly as before, what could be the breakdown? The computer is new, about a week old.

And clarification - the video card is not installed.

(Ed.) I need to understand what part is broken so that I can send it to the store where I bought it. Collected from various stores

Answer 1

The computer is new - bring it to the service under warranty.
They'll figure it out there.

Answer 2

If the amount of RAM has not decreased, for example, as a result of the memory die dying, then obviously this is the motherboard.
I would go into the bios and reset the settings to default.
Well, then hand it over under warranty, with a complaint about whistling and freezing.
Check with the store where you took it, maybe you can still return the mother within 14 days.

Answer 3

How about a mother? Not a power supply?
Does the whistle appear immediately or after applying the load?