No backlight and LCD replacement didn't fix it.
I've been working on an iPad 2 that was dropped. It worked fine, despite the digitizer glass being shattered. I carefully disassembled the unit and installed a new Digitizer. Before sealing the digitizer in place, I tested the iPad. I discovered that the LCD backlight was not working. I reseated all cables. No change. I inspected the unit for any visible damage and found none. I replaced the LCD with a known working unit—and there's still no backlight on the iPad. What else could be wrong?
I have a third broken iPad coming to my department for repair. This time, I am going to let the battery drain 100% before anything is disassembled.
Folks, I appreciate your time posting:
1) Disconnect the battery.
2) Reset iOS.
These things have been discussed here at length and have not resolved the problem. My iPad issue is still not resolved.
As I reflect on my disassembly procedure, I have considered that I did something differently the second time around. The first time, I used a plastic scribe to release the LCD cable from the logic board. The second time around, I used the mini screwdriver from the kit to pop up the retainer. Reflecting on my actions, and knowing better, using the screwdriver probably created a short across contacts and damaged the logic board, despite my working carefully. Of course, I am just guessing—but that was a difference between the two repairs I did. The first iPad repair being successful—the second, not so successful.