iPhone 5S has lines when new glass installed

Ok, I have been searching this problem for hours, and haven't really found a solution. Keep in mind I know little about circutry and that sort of stuff, however I am very quick at understanding and following instructions.

Here is the issue I am having. A woman brought in here iPhone 5S with a cracked glass. Ok, no problem. The biggest issue I seem to have with these phones is getting the backlight clean before soldering on the new one.

I did the first one, and when I put it in, I noticed the backlight was not clean enough. So I took it out of the bracket, re soldered a new backlight. Now when I put it in again, this time with a new bracket I had some yellowing in the one corner. I knew it was because of a screw, so I backed it out a little, and when I turned the screen back on I had lines along the left side. Keep in mind I DID NOT disconnect the screen to back this screw out.

I have tried hard resting the phone. When I plug her original screen in, there are no lines. I have another screen and that has lines all down the whole phone.

Any help? These iPhones are gonna be the death of me. Now we have to put a whole new assembly in, killing all our profit.

Here is how we do it:

1.Buy broken 5S screen on eBay.

2.Remove all glass

3.Remove all glue

4.Put LCD in mold(with backlight still attached)

5.Lay down LOCA Glue (2500F)

6.Remove old backlight

7.Clean back of LCD

8.Solder new backlight

9.Put in new bracket

10.Install

Here is her original screen

http://s28.photobucket.com/user/theemono...

Here is the first one I tried

http://s28.photobucket.com/user/theemono...

here is the sceond

http://s28.photobucket.com/user/theemono...

I keep getting these darn lines. Anyone have any solution. It does not happen on the original screen, but if I plug in one of mine, there are lines!!!!

Thanks in advanced.

-Matt