Laptop Display Quit working

This thread continues one that was recently locked.

Laptop Display No Longer Working

I had the EXACT same problem.  My Dell E6520 is connected to an external monitor.  I turned it on this morning and the laptop display showed a very quick backlit condition then went blank, but the system still booted - with the external monitor now functioning as the primary display.  All the desktop icons were bunched up on the left and the resolution was a lot smaller, but it worked and I could navigate the operating system.

Preliminary troubleshooting showed the system not able to identify any other monitors connected so I started the BIST diagnostic (power down, hold "D" key, power on) and the screen showed several cycles of white, red, green, blue.  So the screen worked, but wasn't getting data.  I then tried to execute the ePST diagnostic but because it apparently uses the laptop monitor exclusively I was not able to see any activity with it and eventually abandoned it.

Called Dell support (my machine was still in warranty - by ONE day!!! - this never happens to me, I'm always OUT of warranty by one day, but God had my back today) and the tech specialist heard the whole story.  Eventually after a lot of back and forth he said that it was almost certainly a problem with the LED cable.  I said "I can check that out while we're on the phone" so I took off the display bezel, removed six screws that hold the LED panel in the top cover, and proceeded to examine the cable.  It was fine except for the fanned out part where the wires are separated for insertion into the flat connector on the back of the panel.  That fanned out part was kinked, essentially folded over itself like it wasn't flat when the panel was orignally installed.  so I unkinked it, turned the panel back over onto the top and pushed the power button.  Joila!  I had video.

They're sending a new cable but this one is working now, even though it might be slightly compromised. 

Bottom line: if you have this problem, take the LCD panel apart (very easy, google it) and look at your cable.  You just might get it working again.  If not, try buying a compatible cable on ebay for cheap (under $20) and replacing it.