820-00850 no video, no post.

[AlexNTI]

Motherboard 820-00850
Turns on, all voltages go up but there is no picture at all.
Whenever I do REVIVE on DFU for the time being there is a picture of an apple and a bar fills up.
After reviving the computer it turns on again as usual with all the voltages but no image on the screen.
Feeling he's no post.
What and how to check the cause of this malfunction?
I'm sorry for my English, it's not my native language.
Please help!

 

[2informaticos]

First of all, welcome to the forum!

Do you get external video and USB activity?
Just in case, try restore too in DFU; only if no important data on its SSD.
Be aware, as restore erase the SSD.

 

[AlexNTI]

Hi, I did revive not restore, this procedure no erasing data.
No, I don't have external video.
How i can check USB activity? I'm just being precise about what you mean
Thanks

 

[AlexNTI]

Now I noticed that after a few minutes of work a computer runs fans on max and does a restart.

 

[2informaticos]

Use a pendrive with Link LED.
If flashes, then you have USB activity.

 

[AlexNTI]

No have USB activity.

 

[2informaticos]

Is there important data on the onboard SSD?
If not, try restore option in DFU.

 

[AlexNTI]

In this case data very important. I can somehow back it up first?

 

[2informaticos]

Didn't enable Time Machine?
Try to see if you can access SSD in Target Disk mode.

 

[AlexNTI]

Time Machine no.
How can I run Target Disk mode? A computer did not turn on. I need to set it in recovery mode.
Or there is another way?
I can access via DFU checkra1n to partition bridge OS, but how to access to partition of user data?

 

[2informaticos]

Same machine used for DFU, check if see SSD in target disk mode.
Google shows you how to boot in this mode...

 

[AlexNTI]

I'm sorry I really do not understand, how can I transfer a computer to a target disk If a computer does not turn on, also not have USB activity.
I'll be really happy if you show me what you're talking about.
Thank you.

 

[2informaticos]

You've said to get image on it, when revive in DFU mode.
Also said it turns on after, but no image.
You don't need image, if you can access its SSD from the other nachine, via USB.

 

[AlexNTI]

With this problem, he came to me, turns on without display and without USB activity.
Wen, i do revive in DFU, while reviving i see in the screen apple and a bar fills up. At the end of reviving Image disappears, the computer returns to the same state. Turns on without display and without USB activity.

 

[AlexNTI]

Hi, I got permission from a customer to delete all data.
I did restore in DFU, this is a fixed computer.
Thanks.