A1708 (820-00875-A) display only stays on when using hdmi

[George's Tech Repairs]

Hey Guys, I have a MacBook Pro A1708 820-00875) that seems to shut the screen off as soon as it boots up. Sometimes opening and closing lid will bring it back but only for a few seconds

But, when outputting video to HDMI both displays stay on no problem. I have ruled out software, reinstalled MacOS etc etc. I have pulled board out but not sure where to start. Nothing is obviously liquid damaged etc

 

[2informaticos]

Check SMC_LID_LEFT/RIGHT and LID_OPEN signals.