820-3115 b

[andrespi]

this macbook does not give video with a good screen, Could you tell me what measures to take initially, the fuse is good

 

[2informaticos]

Do you get USB activity and external video?

 

[andrespi]

yes, both

 

[2informaticos]

So missing both image and backlight?
Check L9004/08/80.
Any history fault available?

 

[andrespi]

PLT_RESET_L=3.3V
Any history fault available?NOT
What is the CPU core voltage after 10s?1.12V constant
Did you try knoen good BIOS?yes, the problem persists; whith chipmunk usb tester, only 5v usb,but no data usb

 

[2informaticos]

When board boots, VCORE should drop to 0.75V approx.
There may be a communication problem, because of bad PCH, or CPU.
Also possible to have bad trace, corroded, or knocked off resistor.
Check the series resistors from SPI lines and LPC bus.