Black screen after replacement

I just replaced cell signal antenna and the power-button/sensor cord and I adjusted the home button, cause it was too tight.

After I was done and put it all together, the screen was white on one half of the screen and black on the other half, after 10 seconds the white faded away and it all got black.

I then turned it off by holding home and power button, then I whiped the LCD and digitizer connectors with a piece of paper, I also replugged the battery connector just to be sure.

When I reassembled it again, the screen wouldn't even turn on at all. To make sure it actually was on, I Connected it to the PC, it turned out to be on, but the phone speaker itself made an beep noise every 5 seconds while Connected to the PC.

What has happened?

Update:

I cleaned the connectors again with Windex on a Q-Tip.

Now it's just back to black screen, but atleast it's on.