ASUS MAXIMUM VIII HERO POWER ISSUE

[mo000]

HI
I HAVE NOTHERBOARD ASUS MAXIMUM VIII HERO powering on and off with cpu 8pin
NO SHORT IN VRM
cpu vcor vccsa vccio apears when motherboard powe up
vccpll missing
i check vddq for ddr4 i found it 1.1 instead off 1.2v ?
i check every coil no short .

[DynaxSC]

Check all 4 RAM voltages (0,6V, 1.2V, 2.5V and 3.3V which sometimes is also a second separate 2,5V), mostly 0,6V is missing due to buck controller failure. 1.1V is strange, should be 1.2V, higher if XMP is on. 0,6V is usually generated from 1.2V, so low 1.2V might be result of too high load (failure) from the 0,6V buck controller.
Look not only for shorts, but also for buck controllers generating no voltage but having its ENABLE pin ON. Not always there are shorts, sometime just the controller is gone w/o short.

[mo000]

Check all 4 RAM voltages (0,6V, 1.2V, 2.5V and 3.3V which sometimes is also a second separate 2,5V), mostly 0,6V is missing due to buck controller failure. 1.1V is strange, should be 1.2V, higher if XMP is on. 0,6V is usually generated from 1.2V, so low 1.2V might be result of too high load (failure) from the 0,6V buck controller.
Look not only for shorts, but also for buck controllers generating no voltage but having its ENABLE pin ON. Not always there are shorts, sometime just the controller is gone w/o short.

you mean ddr vtt ?
but what is the relation ? even ddr vtt is missing but the motherboard should power with cpu
i think ram circuit works fine becase yesterday the motherboard suddenly powered with display and vddq becomes 1.2
i think somthing related to cpu because when test motherboard without cpu 8pin vddq becomes 1.0 v