Will dry heat paste prevent monitor from lighting up completely

[JrMedic]

MacBook turns on but screen won't light up completely, I can see the apple logo if I turn sideways brightness button works?? Did replace with a new screen LCD but nothing .. Can it be the logic board? Can it be fixed??

 

[Zotaccian]

You replaced only the screen, not inverter? Might be it.

http://www.ehow.com/facts_5004007_what-lcd-inverter.html

 

[JrMedic]

Actually I did replace complete top case from another Mac ?? My other Mac.. It's strange looks like its coming from logic board? I read something about heat paste drying ??

I almost ran out of options. Also this happened after a soda spill I did cleaned every single part and everything works a new keyboard was purchased but for some reason the screen won't light up completely... External monitor works fine

 

[Zotaccian]

Dried paste itself will not cause screen to go black or be dim, the only thing it could cause is the heat transfer from the chip to the heatsink to be non-optional and that in turn might cause shutdowns because of high temperature, which in turn might damage the video chip... but usually it just causes the temps to maybe be bit higher, I have this old PowerBook from 2005, never replaced thermal paste and it still works fine.

There has been many cases where Apple machines have contained excessive amount of paste straight from the factory which might be bad.

EDIT: If you have Macbook with Intel chip they also produce very little heat and therefore are not so prone to solder failure as Nvidias are. Of course even Intels do not last forever, but still, rarely fail.

 

[iDutchman]

If you have Macbook with Intel chip they also produce very little heat and therefore are not so prone to solder failure as Nvidias are. Of course even Intels do not last forever, but still, rarely fail.

True. I have yet to come across a white or black MacBook that failed all by itself. I mean, logic board failure. And, I see a lot. *student apple premium reseller job*.

I happen to have a few white/black MacBooks that are work seamlessly and superb after (oldest) 6 years even.

 

[JrMedic]

So what can it be causing this if top case was replaced?