After replacement of front panel assembly red lines and green lines

Hi,

I recently disassembled a water damaged iPhone 6 because I wanted to use the screen for my personal iphone which had a cracked screen. Upon, disassembly the screen was functioning with the exception of the water damaged iPhone 6 dying and a blue screen exposed.

I did research on the blue screen issue and apparently it is a hardware defect because screws were placed too hard or software. I am hypothesizing the issue may be due to the water exposure to the logic board.

After, reassembling on the new phone I got the battery charging port icon & vertical red green lines on the screen. I thought it would be caused by the digitizer cables not accurately being connected properly.

Also, note that I have reassembled this iphone with no volume control up or down buttons the cable was severed upon the smash.

If someone could answer why the red vertical lines upon front panel reassembly would be occurring? I have included a picture.