What can happen to iron?

Question

Iron

So, I have a power supply with 20 pin and 4 pin connectors and a Gigabyte Ga MA770-UD3 motherboard with 24pin and 8pin connectors, you can’t connect 20 + 4 to 24pin, they won’t fit, but if I connect 20 pin to 24, and 4 pin to 8, then the motherboard refuses to work, the power supply is cut down after ~ 1 second. If I don’t connect 4 pins at all, but only 20 to 24, then the board works, the coolers spin, but there’s nothing on the connected monitor, the system also doesn’t start - I can’t connect via ssh.
What could be the problem?

Answer 1

Insufficient power, buy a new PSU
20pin on the motherboard is only used on very old PSUs. Now backwards compatible in 24pin is used.
Similarly with the CPU, they used to use 4 pins, now they switched to 8pin. Also backwards compatible. 4pin is allowed to be used if the CPU will not overclock

Answer 2

How old is the power supply? Years 15? Nice job, leave him to rest.
Such an artifact from the ATX1.3 times, although electrically compatible with ATX2.x (correct connection scheme: 4-pin processor power to the processor, 20-pin to a 24-pin connector), is designed for a different workload in principle. Do not scoff at the pensioner.

Answer 3

20 + 4 is extra. nutrition?