PCH or SIO Dead? Maximus VIII HERO

[baticzek]

Hi yall (sorry for my english)
I got an Asus Maximus VIII hero board that didnt start and react to power button at all. cmos and bios resseting didnt help so I shorted the green atx_enable wire to ground inside the 24pin atx plug and the board startet but code 00 was displayed. After that magically the powerbutton started to work again, but now the board only gives Q-CODE 00. The CPU gets warm and all voltages seem okay. All fuses are good and crystals seem to work. The pch gets warm. I tried reprogramming the bios chip and resetting cmos etc, but it didnt help me. I have boardview for this board but now I dont know what to do. Without the bios chip the board powercycles every second so it seems to read the bios code but doesnt post. Code 00 is now the problem I dont know if its related to the powerbutton issue before.

VTTDDR 0.6v is missing and not shorted when not powered. When I turn on the board (standby or normal) it gets shorted to gnd with 0ohmbyt only if powered i dont know why

The SIO gives always the RMSRST# signal o 3.5v
Caps on the PCH are directly shorted to GND but when standby is turned on the short is gone and and 3v and 1v appears on them.

All voltages except VTTDDR are good and cpu is getting hot (works on oher board)
NO status led are turning on (CPU DRAM LED etc)

Does anyone know what I should do next? Its a nice board so I want to fix it.

[baticzek]

All reset signals except PLTRST are ok. When I force apply 3V to PLTRST the red CPU_LED start to glow and hdd controller led blinks for 0.1sec but still code 00. I dont know why but with PLTRST force enabled the CPU_LED now works but still not detecting cpu. Why?

[baticzek]

Checked the board again. PLTRST CPURST AND H_PWRGD are missing. Removed SR75 that connects H_PWRGD with CPU and PCH. PCH side is shorted. I connected 3v and there was 1A current. PCH got hot but nothing was connexted except my 3v on H_PWRGD. So Im 99% sure PCH is dead and it also probably caused the poweron problems. Its resistance on core voltage is 0.3ohm when not turned on. I will replace PCH and board will probably work again.