main LDC display does nothing, totally black dark laptop display
That is awesome fix for $50. I would like to do the same thing with a very similar issue.
Macbook Pro 15 mid 2010. Got this laptop used at a big discount because it wasn't working.
Symptoms: MBP 15 External display works fine, but the main LDC display does nothing, totally black dark laptop display. I did the flashlight test at an angle and I see nothing. everything else is works great and it boots fine.
I think the logic board and graphics board are fine because the system works fine on an external display. I think it is the connection to the display that is faulty.
Anyone else have any other ideas of what it could be? Any other experiences that can be shared? What else can I do to diagnose and narrow down the problem?
You've already completed two basic DIY diagnosis - external working confirms the problem is not VGU/VGC or logic board, flashlight indicates it is not the backlight.
That an external "works fine" I take it the machine boots, and so the HD/OS is also not a problem source.
That leaves corrosion, connectors, cables, controller boards (a fuse?) & the display it's self as the cause of your problem.. In order of ease and cost start with examining the LVD connector and cable. See this thread for more troubleshooting steps.
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