How to check the power supply?

Question

Power Supply

Hello. I bought an expensive, good PSU, BeQuit, L8-600W.
<Background>
Two months later, there was a noise in the system unit. Turned off. I began to turn it on - the cooler turned on for 1.5 seconds and turned off. And so every time you press the power button. Tried to connect ANOTHER PSU! The effect is the SAME. I took the motherboard to the person (I thought that the reason was in him), he inserted his percent, at the first turn-on everything started, at the second, smoke poured from the motherboard. I went and bought a motherboard. He cut her and his percent. It smelled like burning again. And the percent itself is noticeably a little burnt at the bottom. In short, it turns out well And mother And percent. Logically, the reason is in the BP.
<Question>
The question is how it, BP, can be checked? Cutting it to working PCs is risky, because. if the reason is in it, he will burn half the computer there. On the other hand, it is also impossible to disassemble it (if it is given for paid diagnostics), because he's under warranty.

Answer 1

How exactly did you come to the conclusion that the power supply is to blame? He adequately responded to a short circuit, turning off in time. It could well be a malfunction in the motherboard, due to which the processor shorted. Or vice versa, the percent shorted, the mother burned out.
You can check the power supply by shorting the green and black wires - it will turn on and you can check the correctness of the voltages on all pins with a multimeter. Not a complete check, but still