Why won't my screen come on after digitizer replacement?

I had a Kindle Fire HD 2013 version with a cracked digitizer but the screen still responded to touch and worked. I replaced the digitizer and the Kindle came back on and responded to touch but I noticed finger prints on the inside of the digitizer so I took it back apart and cleaned off the inside of the digitizer. I put the Kindle back together again but the screen will not turn on. I can hear the Kindle turning on when I plug in the power cord but the screen just won't turn on.

I am not sure the problem because the LCD worked before the repair and even worked after the repair. I did not drop or damage the LCD or the ribbon cable. I have tried adjusting and reconnecting the ribbon cables multiple times but the screen just will not turn on. Any suggestions?

I tried another LCD and everything worked fine. I must of damaged the LCD at some point in the first repair attempt and did not realize it.