820-02020 No Backlight

[prodigy83]

Reference Only: REF1137

History on the board, I think the touch bar could have fried some things but I am not certain as I have worked on this a while back, and am back at it again.

I can see picture externally on a display, and also on the LCD screen, just no backlight.
LPDP_INT_HPD does not go high.
I have replaced: QP800, QP801, UP800. CP600.
DP800 pin K gets .048, A slowly drops but at .048 and still dropping.
I dont know what else to do?

 

[2informaticos]

LPDP_INT_HPD must be high to enable internal video.
You've probably measured in wrong point.

Did you test with known good LCD assembly?
Do NOT use Intel screen for test; you may kill the M1 processor.

Do you get 5V_SW_LCD_CONN?
Check for correct 1V8_AON at UC120 output.

BTW, all voltage checkings in backlight area must be done with LCD connected.

 

[prodigy83]

LPDP_INT_HPD must be high to enable internal video.

I went back and checked RP611 Pin 1 and there is definetly no voltage. I tested on my external monitor again and it recieves a signal but never any video.
I do believe I hooked up one of the intel displays. Fried?
When I tried to turn the computer on, the fan spins up real fast.

 

[2informaticos]

A2337 820-02016 PPOV805_S1_VDD_FIXED shorted

Hey guys, Just wanted to pick your brains and see if anyone has experienced this before.. We’ve had 2xA2337 MacBooks in within the last 2 weeks for screen repairs. Both came in fully functional but just had screen damage (could see image and lcd damage) Not quite sure what one of our techs is...

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