Graphics Card Switching Disappeared and No Brightness Control

[Rmafive]

Hey guys,

I've got a really strange issue that I am hoping to resolve on my own. I recently got my logic board replaced for a faulty graphics card (about 1.5 months ago) and my 15" rMPB has been working great since. However, I just ran into a problem after opening the lid tonight. I cannot control the brightness via the keys or system preferences (the controls ahve just disappeared). Also, GFXCardStatus tells me that my system is no longer compatible (I apparently don't have a dual GPU system anymore) at startup and I cannot select the GPU switching option in the energy saver preferences.

I believe I am running on the discrete GPU (according to about this mac), so I wonder if this is a problem with the CPU/integrated card.

Further steps I have taken:

• Reset SMC/PRAM
• Restarted multiple times
• Booted in safe boot (same issues with brightness/settings missing here)
• Ran a diagnostic with no errors returned

Let me know if you have any ideas before I resort to another trip to the genius bar!

Edit: Another issue I forgot to mention is that the boot status bar during startup appears both in the center under the apple logo and on the very bottom left of the screen during boot. This is such an odd issue!

 

[Rmafive]

Update if this ever happens to anyone:

It turns out that the top case (a piece that connects the logic board to various other components including the keyboard) connection is damaged on the logic board, so it will have to be replaced.