820-00928 Appears to be turning on. CPU & GPU. DFU not recognized.

[SolderFungus]

Hi. I have a 820-00928 that appears to be turning on but there is no image or sound. No image via thunderbolt/ HDMI either.
I tried DFU but I get a "thunderbolt device not recognized" message.

CPU & GPU is getting hot. 20v on USB-C meter.

I'm not sure what to measure or look for as it appears to be fully operational. Asking for advice from the professionals!

 

[2informaticos]

Why DFU?
It is not T2 machine.

Check CPU core voltage behavior?
It should drop to 0.7V aprox when board boots.

 

[SolderFungus]

appears to star at 1v and then it drops to 0.9 relatively fast
PPVCC_CPU_PH1 0.9V
PPVCC_CPU_PH2 0.9V

Is 0.9 too high?

 

[2informaticos]

Then the board doesn't really boot.

Any history available?

Try known good BIOS.
Make a backup first.