A2779 820-02841-A black screen but not in recovery

[thomamagic]

Hello, I have a problem with a MacBook Pro A2779 820-02841-A when it starts up the apple logo is displayed and as soon as the session starts the screen goes black.
I've tried a reinstallation, a DFU, unplugged keyboard, trackpad, battery, angle sensor, but nothing changes, no trace of oxidation on the motherboard.
Do you have any ideas?

 

[2informaticos]

Couldn't complete DFU revive/restore?

 

[thomamagic]

In dfu revive
Machine start we have sound for select language but Black screen
We enter in recovery mode and screen works but not in os

 

[2informaticos]

Sound in DFU mode???

 

[thomamagic]

After dfu restore finish machine start and yes i have sound for select language

 

[thomamagic]

I have make revive and after restore
The 2 are working sorry for my explanation

 

[2informaticos]

So you can even complete recovery, but no image after last restart?

Just in case, complete the recovery using external monitor.
Then let see what happens after finish installation.

 

[thomamagic]

With old screen same, with new work 1 min and cut, on external perfect after finishing installation

 

[2informaticos]

After 1 minute, disappear both image and backlight?

 

[thomamagic]

exactly
and now no image same in recovery mode
just for check, on LP800 normally need get 10V and have 6.2V
maybe UP800 defect?

 

[2informaticos]

Just backlight not working.
However, image MUST appear first.

If no image, no reason to check for backlight.
Backlight is always delayed to avoid any artifact, until video communication is stable.

 

[thomamagic]

any idea what to look for?

 

[2informaticos]

What customer said about fault appeared?

 

[thomamagic]

Working normally and 1 day this problem
no water damage, check with microscope nothing

 

[thomamagic]

news?

 

[2informaticos]

Test disconnecting lid sensor.

 

[thomamagic]

already test, remove and replace same

 

[2informaticos]

Do you still get 1 minute image?

Check what happens in recovery menu.
Can you choose Share Disk there?