POST fails on Maximus VII ranger. Replacing the power supply, RAM, reset cmos did not help, what should I do?

Question

motherboards

Hello!
There is a maximus vi extreme motherboard.
After not careful cleaning, it stopped turning on.
The motherboard was replaced with a maximus vii ranger - the problem remained.
What we tried:
1) Replacing the PSU with a new exactly working one
2) Reset cmos with a battery and a special button on the motherboard
3) Config with and without RAM
4) Completely disabled peripherals

Answer 1

Those. took another, obviously working motherboard and it doesn’t work for you either?
Obviously, you need to look for a part that was used in both cases - it does not work!
Taking into account your list, the processor remained - the first candidate, it is not very clearly written about the memory - the second, well, and the third, albeit outlandish, but theoretically possible - the case and all the connections, you never know where they could arrange some kind of short circuit.

Answer 2

The pins of the Power button are not connected there.

Answer 3

Have you tried running the motherboard directly, bypassing the case? This is easily done by closing the contacts responsible for starting the PC, but be careful with this, close exactly the right contacts.