820-3462 No picture after Catalina upgrade

[overshoot]

That's at least what the customer is telling us.
No sign of liquid damage though the board doesn't look great.

I am focusing on the Bios for now. I believe it could become corrupted after a failed upgrade or something.
Symptoms are we can't do a PRAM reset nor access the EFI boot menu.
Screen stays black though we have backlight.

Can someone share a Clean dump of a 820-3462 bios please?

 

[2informaticos]

Try this one, as is...
https://drive.google.com/open?id=1JX72ET7y-Cq-JGJhUosORVLQ0EX5qIeU

 

[overshoot]

Thanks!

Actually trying a donor board Bios (old bios), I am now getting a picture on her screen and our test screen.

I am wondering if it could be an EDID ban of her screen. I will try your Bios anyway just to confirm.

Is there a list of banned EDID screen codes somewhere to compare please?

 

[2informaticos]

So machine works after OSX upgading, only missing video on internal LCD?

 

[overshoot]

Machine was turning on, CPU was getting voltage but it was brain dead after the Catalina upgrade.
We're now getting it to boot with your Bios file.

Thanks!