I'm current 75% complete on converting a black iPhone 4 to white. I've replaced the front panel & LCD, back panel, and dock c...

There is one leg that needs to be clipped completely off, and one of the corners needs to be slightly trimmed (or completely cut off) to accommodate the screw, but otherwise, it's do-able.

I seem to have this problem most commonly with white aftermarket digitizer/lcds. Some work, some don't. I just always have more than 20 at hand to find one that works best. Funny enough, one that doesn't work, seems to work fine on another. There must be some sort of "weird" compatibility with each phone. I can't give you much input, except that some screens seem to work while others just don't.

This piece goes underneath the top screw of the battery terminal. From the picture, flip it onto the bronze side with the black "leg" on the right side. Slide underneath the battery and run the top screw through it.

The problem you describe is not sleep button issues but rather battery issues. It seems you may be having a problem with your battery connector. Have you verified that the battery connector is fully seated in the board? How about disconnecting it and inspecting the 4 little prongs on the terminal? If those seem to be okay, there's a possibility the battery is faulty through physical damage of the battery contacts or cell damage.

Sadly, the only fix for this is to remove the glass and probably bend the frame back out. Most likely, your volume key is pushed in by the damage of the drop. Best of luck with that friend.

This has probably been beaten to death but I thought I'd put in my two cents. Working in a repair shop for these phones all day, I can say with all certainty that using an iPhone 4 display can be used in place of a 4S display. What we have done when we ran out of the 4S displays is substituted with a Verizon iPhone 4 display. We use that one because the hold-down legs are nearly identical except for one which is impeded by the sim card slot on the 4S. We just simply snip that one off and everything else bolts in properly. As stated above by a few people, the ambient light sensor does not work as the 4S has a different location for it.

There are two possible reasons for why your phone isn't picking up your voice. 1. You are having a software issue. Since you said you never dropped it or had it come into contact with water, there is a possibility that you just need to do a software restore and it may fix the issue. 2. The bottom microphone isn't working. The microphone at the top seems to take over for picking up your voice when you go to speaker phone. Try disassembling the phone and reseating the connector which is right next to the battery which has a metal plate being held down by two screws. If reseating the ribbon doesn't fix it, then the microphone needs to be replaced. The microphone is attached to the dock connector so it will all be replaced in one component. There is a third possibility which is a malfunctioning headphone jack, but since you stated that you can hear from the earpiece while on a call, then that tells me that you are not having the headphone jack issue that I suspected.

You can take a little bit of paper and hold it over the screw and push the driver into the slots and turn it. The paper will attempt to fill the gap and allow the driver to turn the screw. Hope you resolve your issue.

You have an issue with the headphone jack. Your phone "thinks" that a headphone is plugged in thus outputting music to your headphones which are actually not plugged in. This explains why your phone still plays tones, and alarms because those will use all outputs due to the importance of those notifications. As stated in another answer, try cleaning the headphone jack. If that doesn't work, then replacing it will most likely fix the issue.

Since you have replaced the screen already and done a software restore, the problem repeats itself tells me that there is a issue with the connector. Most likely, some of the pins are making poor contact. You can try to inspect them closely with a scope and see if there is something blocking the contacts such as corrosion or foreign material. If there is nothing wrong, then there is probably a problem with the logic board. Sadly, I don't have the knowledge on what to do there.