820-3437B Faulty CPU?

[Bouba148]

Hi 2Informaticos, Team

This board came perfectly clean no WD signs
It boots fine but no chime and no display, USB activity OK .
All S0 rails present and fine, CPU heats quite a bit more that usual.

PP5V_S0 : 5.123V
PP3V3_S0: 3.318V
PP1V05_SUS: 1.058V
PP1V5_S0: 1.508V
PP0V6_S0_DDRVTT: 0.599V
PP1V05_S0: 1.051V
PP1V05_S0SW_PCH_HSIO: 1.040V
PPVCC_S0_CPU: 1.735V

EDP_BKLT_EN: 0V ===> CPU

I will pass it in the UC and see if maybe crap underr CPU.......
Could it be SPI to CPU Serial Bus? I 'm asking myself because I don't know if usb activity OK means only SPI mode OK or both SPI and CPU in that case serial bus would be OK.....

 

[2informaticos]

Are you sure about USB activity?
Confirm with OSX pendrive with Link LED; if flashes, there is activity for sure.
Do you get external video?
Did you test another LCD assembly?

 

[JohnB8812]

Likely trash but try BIOS and all that 2informaticos suggested.

 

[Bouba148]

Hi 2Informaticos:

Are you sure about USB activity? Optical mouse turns ON
Confirm with OSX pendrive with Link LED; if flashes, there is activity for sure. Tested with external 10.12 SSD HFS with led: led turns ON but not blinking as it should be, so No activity, only power like usb mouse.
Do you get external video? Tested with Thunderbolt VGA/DVI/HDMI adapter and No Video on any on these outputs
Did you test another LCD assembly? Yes

 

[MOMOH]

I would suggest you grab U6100 from a donor board just to rule out the SPI ROM CHIP and then see if it still stays the same.

 

[Bouba148]

I've forgotten to mentionned that I'm able to read the U6100 informations and lloks like OK, I've also cleaned the ME Region, but still the same.
I don't remember if I've injected another dump file into it but I can try.....

 

[2informaticos]

Try different BIOS file.
Cleaning ME region doesn't help if main BIOS area is corrupted.