How to solve this problem with the cooler and PSU?

Question

Video cards

The computer shut down in the middle of the day, feeding me the smell of burning rubber. I immediately went to investigate and immediately discovered that the cooler, as usual, moved slightly away from the processor. I fixed this whole thing. But the PC did not turn on. Instead, the fan on the GTS250 1gb graphics card was twitching as it tried to spin up. No rubbish bothered him. The CPU cooler was spinning. True, unstable sounds were heard, as I understood from him, as if the speed was increasing and decreasing (WHUUUVZHUUVZHUU, instead of the usual ZHZHZHZHZHZh). From BP terribly carried rubber. I immediately cleaned it and checked all the connectors and wires in the system unit, removing and inserting them just in case. Did not help. Then I changed the PSU to another one a little more powerful. Let me tell you right now, it works. And everything is exactly the same with the same smell. Motherboard - MSI MS-7507.

Answer 1

The motherboard most likely burned out, the percent can also. Touch the chips on the motherboard - maybe some are very hot from breakdown. Measure the currents on the main power lines.
The motherboard can be in an on-overload-off-on cycle. That's why the howls and twitching of the cooler.

Answer 2

If there is a PCI adapter-reader for POST codes, you can understand exactly what the download stumbles on.