Step 0: It always reflects more favorably on the submitter when the submitter posts a question to a relevant place, instead of stopping at the first place he/she came to.
Step 1: check your lightning cable connector. In my experience, the 3rd pin from the left (connector end of cable pointing to you) develops carbon build-up (and even pitting, as if from electical arcing.) Use a q-tip with alcohol to clean these 2 pins on the connector. You may get better results from using an alcohol-soaked wooden toothpick. This applies to pins on both sides (“top” & “bottom”) of the connector. With the phone off, do the same for the matching contacts on the phone’s female lightning socket. When cleaning the socket, move the alcohol tool (toothpick) in and out, along the direction of the contact. If you rub side-to-side, you will likely push the socket contacts out of alignment.
Step 2: if step 1 doesn’t improve things, then exert a little more effort to find a relevant page for your question on this site.
Note for reassembly:
On the top end, between the earpiece speaker/front-facing camera bracket and the shield plate is a large section of black ribbon cable that has a large metal box afixed to it, and a 3-wire cable taped to it at its right end.
Remember to place the large section below the box *under* the shield plate before you start screwing it into place!
Refer to the picture above, where the earpiece speaker/front-facing camera bracket is removed.
Given this huge piece of adhesive & the finesse required to deal with it, it seems a better instruction would be along these lines:
* Only remove the home button cable from the shield plate if the shield plate is damaged.
* If this plate is undamaged, and you are replacing a frontscreen assembly with its own plate, then simply move this plate to the new assembly.
Thanks to @griffn & @adlerpe! I've updated the tools list to include the magnetic pad, and -- for us infrequent fixers -- I made a note in the intro text to describe the sort of thing you two noted here in place of the mag pad.
Also, to @damianodessgillett & @kev - I've submitted an update to the instructions to add the caution you recommend to the step. Hopefully others will avoid the pain of the Long Screw damage.
@girlsrock742 - I'm new here, but from what I've seen, questions like yours don't get answered. I have 2 suggestions:
# Be more specific about what your issue is.
# Make sure you're using the right screwdriver. (Get a magnifying glass & make sure the screwdriver fits nicely in the screwhead.) This guide is included in a guide I'm looking at, and my guide has a comment that #000 phillips is required for the battery connector bracket above, not #00 as documented. (That comment did not convey to this guide....)