820-3023 boots to white screen

[Don Anton]

HI,

This is not any damaged board. when it turns on chime and white screen remains.

Removed a ssd and tried to boot from usb same issue. Did pram, Clean me region using medusa no change.
Tried another screen same issue. I get 26v on C9017. L9004 3.3v.

Really appreciate your advice.

 

[2informaticos]

This is eDP, so looks like bad LCD, or video cable.
Be also sure LCD connector is OK.
Check diode mode to ground on all data lines; w/ and w/o LCD connected.

Best way, test known good full LCD assembly.

 

[Don Anton]

Hi thank you for your reply.

I took the board out connected good known LCD and only external hard drive to see whether hard disk is reading. still it stays on white screen and external hard disk only blue power light. No reading red light.
I tried with our the screen only power connected to the board and the external hard drive. still not reading from external HDD. So seems line logic board issue.

 

[2informaticos]

So you don't have USB activity for sure?
Dou you note a drop pulse 1.1-0.8V on CPU VCORE?

 

[Don Anton]

Yes when it boots CPU VCORE Drop from 1.1v to 0.8v and remains in 0.8V

 

[Don Anton]

After dropiing down to 0.8V it stays stable 0.8V

 

[2informaticos]

Mmmmh, this is 3023; I was confused with 3115.
I don't think drop pulse is correct here.
Compare with known good board if possible.

Very strange to chime, but no USB activity; did you test both ports?
Do few times PRAM reset.
Try new full BIOS too...