iPhone 5s Not Powering On Since Screen Replacement

Hi guys,

I have an iPhone 5s I am fixing for a friend. The screen broke a few months ago so I ordered a replacement and fixed it absolutely fine.

It has since been broken again and I am doing a second repair. I have take off the camera, grounding ribbon cable, home button etc. The grounding cable that sticks to the metal back of the screen has lost a lot of its stick.

I put the new screen on, reattaching the home button (I believe I may have got the plate wrong on the single screw and it now touches the metal on the back of the screen. I screwed the square plate back over the 4 ribbon cables (including the battery cable). Reattached the home button cable and cover.

At this point I switched the phone on. The apple logo came up, but when the phone hit the home screen the sides were shimmering and the picture began to deteriorate, changing from good to severely distorted. I turned the phone back off, tried to readjust the cable, switched the phone back on, same thing.

I redid the cables for a third time and now the phone will not switch on. I am currently testing with the camera etc not plugged in. So just the two cables from the lcd and digitiser. I have double checked the battery cable is in properly and also tried the same scenario ie two cables with the old screen. Neither now show anything. I have tried with the home button re-attached and holding both the home and power button, but nothing.

Does anyone have any idea what could be wrong. Are all components necessary for it to turn on ie camera, home button etc. Could the plate on the single screw of the home button touching the back metal have caused an issue. I cannot understand how it could possibly just stop working within a few seconds unless some surge or shock has been caused. Any help or advice would be greatly appreciated.