Display issues, darker on one side of the screen
I'm sure this has been asked before.
I replaced the battery in my friend's MacBook yesterday without a hitch and the display was fine.
My friend contacted me last night to tell me the display brightness is off, it's darker on the left side and normal brightness on the right.
I tried zapping the PRAM, resetting the SMC and even ran the AHT (Apple hardware test). The AHT said no issues.
I took a photo of the display and its attached. It might look like it's completely black in the photo but in real life, it's just darker.
Is the display going bad, (inverter cable or LCD cable), a graphics card issue? If it's the display I could replace the display entirely or cables myself.
My guess is it's the display, inverter or LCD cable perhaps.
If you need more information, let me know.
MacBook 6,1, unibody, late 2009, OS X Yosemite, 10.10.5. 8GB of RAM.