Macbook Air A1932 820-01521-A black screen

[Djsp]

Hi I have this machine with the black screen, usb meter goes to 20v and reaches 1.56 A caps lock makes the green light the screen remains black, I tried an external monitor but nothing. How can I proceed?

 

[2informaticos]

Test external video disconnecting internal LCD.

Any history available?

 

[Djsp]

I tried to disconnect lcd, but nothing, the fan turns but no video

 

[2informaticos]

Caps Lock light still reacts?
Did you test USB activity (not power)?
Did you test with known good (compatible) LCD assembly?

 

[Djsp]

I inserted a na usb pen and there is usb activity, the caps lock responds when it is pressed but I don't even have video with an external monitor, and the fans run fast

 

[2informaticos]

"Any history available?
-------------
Did you test with known good (compatible) LCD assembly?"
???

Full fan speed can be caused by bad/missing battery.

 

[Djsp]

Yes in fact I disconnected the battery when it comes to the story, I have no information, the machine presented this type of defect all of a sudden, now I try with another external monitor, could it be in DFU mode?

 

[2informaticos]

"could it be in DFU mode?"
Check that too...

 

[Djsp]

I tried with DFU mode, but the image of the DFU is a padlock tried the restore but I get this error com.apple.MobileDevice.MobileRestore – 0xFA0 (4000)]

 

[2informaticos]

Does it appear directly into DFU, or you've put it using keyboard?

 

[Djsp]

Appears directly

 

[2informaticos]

Padlock sign should appear only after DFU is completed.

 

[Djsp]

I redone the procedure, it enters the dfu, I proceed with the reset, but I also tried with the reactivation, but the procedure ends with the lock, I also tried the reset of the pram, it emits the sound but no screen, the T2 is gone or is there any other problem?

 

[2informaticos]

Tested known good internal LCD???

 

[Djsp]

Yes I did but nothing, having to do in visual inspection on the board which points might be interested maybe the IGPU section

 

[2informaticos]

Missing both internal/external video, points to iGPU...

 

[Djsp]

Then allo probably will be the Nand memories in dfu mode when it tries to restart to re install the operating system goes in bulk

 

[2informaticos]

If machine chimes and has USB activity, is not in DFU mode.
It works, but has graphics problems.

 

[Djsp]

After the holidays, I took a look at him again, and found the culprit, the problem that the cut is at the limit.Flex is cut