Home PC just starts up for a fraction of a second and that's it. What Causes?
Answer from: qntan:
Most likely, some device in the computer in a short circuit and the card is included goes initialization of devices and the code reaches this device on the board triggers protection and power is reset. It could be almost anything network card, audio codec, hard drive, video card, etc. To find out you need a complete diagnosis, and it is desirable to carry it out in a trusted service center. At home it is impossible to conduct a detailed assessment of possible malfunctions.
I hope the answer was helpful.