Why is the motherboard cut out?

Question

Electronics

Hello all hard workers!
Now I will try to describe the essence of my problem as accurately and juicy as possible.
In general, I have a motherboard that seems to have seen life.
At first, one guy had it, then another, then another, and now I have it :)
As a result, I am the fourth in a row. And this path began because guy #1 started to cut down the computer, by the method of elimination it was deduced that the motherboard was to blame, as a result, without worrying, he just assembled another computer (he had been planning for a long time and it’s just a coincidence), in the end he didn’t become with her take a steam bath and gave it to his friend - guy #2.
He gave it to him with an i3 530 processor. He did not sit on it for a long time, waited out the accumulation of money; already with a new block, RAM, video card, hard drive, only the processor was the same.
He also didn't mess around with her, built a new computer and gave it to his friend - guy #3. The situation is identical, the processor + motherboard, the rest of the components are their own, it waits one month and completely changes the system, without understanding what and how. Then, as I found out, she lay in the pantry for one year. And I got it, only the processor I used my I5 750, the rest is the same, everything is mine, well, except for this very mainland. And so I am writing to you, I have already written to several forums, everyone is talking about power supplies, overheating (hehe) and as soon as it comes to the fact that I provide temperature charts and the type of motherboard, everyone frantically shrug. It looks perfect, nothing swollen, not dirty. All elements are in place. Hmm, to the point. When the motherboard cuts out, it throws the power supply into a short circuit, i.e. I can’t turn it on right away, I have to switch 220V. temperature is normal, it immediately occurred to me that mb sensors are lying? I began to feel with my hands, not a single element was heated so that I could not hold my fingers for ~ 10 seconds. Everything is cold. There are a couple of assumptions and investigations: it cuts out at random when there is a load on the percent or video card, i.e. the load is growing, and so far. Basically, when the video card is loaded, but this is probably due to the fact that the overall temperature under the case rises faster and it is extinguished. The temperature level when cutting down the processor = 44-50 degrees and then it just goes out. There is another problem that when I insert the 24pin connector into the motherboard from the power supply, when you insert it all the way, the standby power appears on the mainland, but it does not start, you need to slightly lift the plug above the connector, in the end everything works. I hope I wrote it as clear as possible for you and you will not have typical questions.
UPD # 1: I tried to exclude CPU overheating, pulled out the heatsink completely on the CPU and went into the BIOS, after 10 minutes of sitting like this, the temperature showed 60 or 65 degrees and everything continued to work, there were no problems. Those. in bios does not cut down.

Answer 1

Take it to some service center if you are interested to find out what the problem is and fix it, if not, then just dispose of it. Probably some capacitor just broke there, who can guess ...

Answer 2

this is electronics on mom junk, which transistor or mosfet, you need an experienced electronics engineer to raise mom.

Answer 3

mechanical damage in the soldering of the "sandwich": "There is another problem that when I insert the 24pin connector into the motherboard from the power supply, when you insert it all the way, the standby power appears on the mainland, but it does not start, you need to slightly lift the plug above the connector, in the end everything works."
the resistance changes during operation depending on the load, and here are your reboots.
in general, this may be a repair case, but most likely not if the problem is in the center of the sandwich. this is not a factory defect. your "friends" tell you stories. the board was bent, broken. such things travel by collusion. when they burn, they immediately fall into the bucket.
change friends.

Answer 4

He took it to the sc, the "master" twirled it, shrugged it off, asked around, in the end he said he couldn’t help :)