Why does the computer shut down after three calls?

Question

Electronics

A system unit based on the Z68 board from Gigabyte with a Core-i7 2600, Windows 7, everything was fine, but an unpleasant feature appeared, in the speakers I hear three “wheezes” similar to interference in the mains and the computer is cut down or rebooted, this happens several times a day, moreover if it is cut down, it does not start any more without completely turning off the power. I would understand if all the equipment behaved this way, but two more are working in the next room and this is not observed. Most likely this is nutrition, but what exactly and what are the reasons for such non-systemic behavior, I could not trace the pattern, it falls both cold and on the move, percent. does not overheat. Has anyone had similar problems?

Answer 1

Breakdown-spark-interference-blocking.
Disassemble the device and look for a place of charring. Possibly in the power supply itself. From the board to the case. Through careless soldering and melted insulating plastic.

Answer 2

check if the computer responds to pushes-bumps-jumps on the floor

Answer 3

Perhaps some chip on the motherboard was poorly soldered and, due to thermal deformation, the contact began to move away there. This sometimes pops up by itself after a few months of use.

Answer 4

Is there an uninterruptible power supply between the PC and the mains?

Answer 5

If possible, check by replacing the power supply. If not, look towards the motherboard.