[SOLVED]3332 black screen - Not U8900

[G.Beard]

Hi.

Got a board here that was liquid damaged.
U9000 was shorted, replaced U9000 and caps.
Screen-side eDP connector was totally fucked so replaced also (screen now works perfect on this and another machine).
Replaced J9000
Replaced U9100
Replaced R9018
Touched up U8900 with the iron too.

This machine will boot to installer and black screen. Close the lid and re-open once fans no longer spin, the screen then displays.
Boot into OS gives black screen. Close the lid and re-open, still no image.
Boot into Linux Mint, all good, no issue.


Liquid damage was also around the GPU and VRAM.

My guess is some crap got under the GPU or VRAM but I'm posting in hope.

 

[larossmann]

In Linux mint which GPU is it using?

 

[G.Beard]

In Linux mint which GPU is it using?

iGPU I guess but....

Hmm, now in OS X if I plug in a mini display cable the internal screen wakes up. Internal will stay working if external is removed.
Restart with internal only and back to the no output until I plug external display again.
Start the machine up with external plugged in and both int and ext screens work.

Any ideas?

 

[G.Beard]

So it's working from the iGPU once external is plugged and unplugged.
It's working from the GPU when monitor is plugged.
It does fuck all when booted with only internal screen is in use unless monitor is plugged and unplugged.

So what is telling the output to wake up?

 

[dukefawks]

Check HPD line from LCD connector.

 

[G.Beard]

Check HPD line from LCD connector.

.... Oh..... well this is embarrassing

 

[dukefawks]

Uhm, is this fixed then?

 

[G.Beard]

Uhm, is this fixed then?

Yes.

Thank you for your help and for reminding me I'm a dumbass!