Why is screen black after replacing hard drive?
I just replaced the hard drive on this 21.5" mid-2010 1Mac.
All went smoothly, except... the screen now stays black at startup.
The screen appears to be totally black. There is no evidence of any backlight activating.
I tested with an external display connected via mini-dv, which works fine.
The first 3 internal diagnostic LEDs all light up, but the 4th remains dark.
If LED 4 is ON it indicates "... that computer and LCD panel are communicating. This LED will be ON when computer is turned on and video signal is being generated. If LED#4 is ON and there is no image on display, then the LCD panel, the LED backlight board, or the cables between LCD and logic board or backlight board might be installed incorrectly, or need replacement."
Since LED 4 is off, I deduce my computer & LCD panel are not communicating.
I am hooping I can just get a replacement cable to fix this. Is there any further troubleshooting I can do to determine which cable to replace?
The video/data cable, the backlight cable and the vertical hold cable, all of which have to be removed for this upgrade. Perhaps one of them was damaged. My money would be on the video/data cable since this was a pain to re-connect... but is there any way to test?
Is this a good question?