LCD BACKLIGHT and no F1/F2 response
I recently bought a second hand MacBook Pro 15" mid 2012. I thought I could upgrade to 2 SSDs. Upon checking the F1/f2 brightness o roll were not responding. I could see the indicator on the screen where it'll show the brightness going up and down but actually the LCD doesn't becomes brighter or dimmer.
The seller said its due to a software bug. The system was at El Captain. It was stupid of me to believe him.
I bought it and updated to high sierra thinking it would fix the problem But no.
Second problem I found out was that once the system goes to sleep, the backlight won't come back on until I open up the back cover and unplug and replug the battery again.
I went to the Apple Store to get it check and they found a unauthorized modification made to the logic board. Here's are the images. You can see a copper wire connected to 2 fuse I suppose