Macbook A1989 - No display/image

[Dallas90]

Hi everyone,

I need your help with this repair that I'm working on at the moment, it's a Macbook Pro A1989 board number: 820-00850A.
When i got the laptop from the customer the laptop just booted up with the charger connected but with no display or backlight.
i found out that the charging ports were slightly burned so i replaced it but the fault was resolved, so my next step was to check the board and found out that
both charging Ic's was faulty and i ordered 2 new ic's and replaced them.

After i replaced the ic's the laptop boots up and keep running even if removed the charger, but the display is still dead…

then i started to take some measurements on the LCD connector and i think a found a abnormal reading, on pin 1 the reading should be 0.226 according to
Paul daniels boardview software, but on my board i following readnings: 0.002 diode mode and 2.6 in ohms mode.

So my questions if anyone got any ideas what the fault could be? What i could see is that pin 1 is directly connected to the CPU
Is there anything else that i could check or do?

I would really appreciate your expertise guys.

Thanks in advance.

[reformatt]

This is a pretty standard fault when you get liquid damage in the LCD connector. Backlight voltage is right next to that data line. With liquid damage the 50V goes directly into the CPU. The 15" A1990 you get away with it as it fries the display MUX chip instead. But on A1989, you're up for a replacement board or CPU, or just run the machine headless to external display.

Not like Apple didn't know about this design SNAFU either. They repeated the same flaw from the 2016/17 MBP's to the 2018 models and above.