GK7MR0R Does not start

[master3112]

Hello everyone.
I have a GK7MR0R (XMG Core 17) The device does not start. When I press the power button, the device tries to start and draws 0.8A for a second. According to the schematic, the following voltages should be present in the connected power supply unit and these are also present:
+5VALW
+3VALW
+3VALW_PCH
+1.8V_PRIM
+1.05VO_OUT_FET
The battery is being charged.

First I tried to rewrite the BIOS, same behavior.
Another user had the same behavior and his chipset was defective. I also changed the chipset, same behavior.
I disconnected the GPU and CPU inductors as a test, same behavior. I have not found a short circuit anywhere.
I have no idea what to do next.
Can anyone help me?
THX

[master3112]

I have made further measurements. I have noticed that when the power button is pressed, the GPU drivers Q166,Q170,Q171,Q172 and the GPU RAM drivers Q173 and Q177 are for a short time active (thermal camera). 3V3 is for a short time present on all drivers at PIN 20. I measure 0.8V at output PIN2+3+4. A GPU is already low impedance, but I measure at inductors L63,L64,L65,L66 =0 ohm. Only at inductor L67 and L69 (GPU-RAM) I have 32ohm. I would say that the GPU is defective, right? How low can the resistance of a GPU be? Under 1 ohm? However, when the GPU inductors are disconnected, the device does not start because the output after the inductors is monitored by the U1903 and U28.
I have also measured the CPU driver U13 PIN 20. There, 3V3 is also present at PIN20, but the driver does not become active.