iPhone 3GS Battery
When I unscrewed it, the spring contact part moved too & the little prong rotated under the cable. I thought (mistakenly) that this was its intended position. The screw also came loose, which made reassembly difficult until I saw that 2nd photo above and realized what the orientation was supposed to be.
The order is screw -> cable hole -> spring contact -> screw hole.
The rounded edge of the spring contact should face the bottom of the phone to match up with the hole’s rounded edge. The perpendicular ‘lip’ should sit flush against the metal plate. The prong should stick up toward where the screen will be. Really, there’s only 1 possible way to put it on correctly, but without seeing the correct orientation first, or if the screw detaches from the cable, it’s kind of a pain to get them back together.
3 times I’ve had to repair my 5S & this was the most frustrating part each time. This time I cheated & just placed the cover back on top of the cable & closed the phone up. No clicking or sliding or fumbling with it. Look at it from the left side & it’s a bit easier to see where it winds up, but I didn’t fuss with it. Phone works fine now anyway.
Where can I suggest that iFixit add a cross-referenced note/warning when purchasing a replacement battery (or other parts that require odd tools) that you also need to purchase yet another special-purpose *&$%#(%@ screwdriver, "because Apple"!!
I had to wait for weeks to find time to complete this repair, and now have to wait weeks longer for another chance.
Note to self: read the entire guide before purchasing, AND before starting the repair, AND while you're doing the repair...
The adhesive strips broke almost immediately. Tried the dental floss trick a few times, credit cards, guitar pick, more floss, hair dryer, etc ... Bent & smashed the old battery to the point I was really worried it might explode. The only thing that really seemed to help was heating up the back of the phone first w/a hair dryer, then jamming plastic cards in from the corners, top & bottom (being careful not to bend or smash other things) until I was able to pry it loose.
Comment above was made on the Lightning Connector replacement guide - I guess it got pulled over here since as well since the steps are identical ... Anyway careful not to smash the bottom bracket w/the replacement battery or adhesive
Notes on the 3 parts from the original you need to remove and reuse for the replacement:
1) The rubber mic cover pulls off easily. Expose the adhesive on the bottom of the new mic, and slide it into the slit in the rubber cover. To reassemble, this bends 90-deg to align the holes in the rubber cover w/the small pegs on the body of the phone.
2) The "home button bracket" : remove it & pay attention to orientation & how the home button connector bends back on itself. The original bracket has some adhesive/foam to keep the connector in place. The replacement does not have this, so there's no easy way to set the button connector for reassembly - it kind of flails around.
3) I missed the comments about the headphone jack metal grounding strip until after I'd already closed up my phone. My standard iPhone headphones still work fine w/o it, but if you leave it out you could presumably wind up w/buzzing or static.
There's the tab to the left of the speaker, as well as a small plastic bit at the top that needs to fit under the logic board. If you skip steps 25-34, you can still remove the speaker & proceed, but be careful of those 2 parts when taking it apart as well as putting it back together.
Reassembly: The left edge of the speaker has a thumbnail-width groove into which you can seat the antenna to ensure it's out of the way. You can use your thumbnail in this groove to slide the antenna wire back & forth until it's in the proper position to snap it onto the connector. Trying to reattach it connector-first was frustrating as the part is very small & difficult to maneuver that way.
As long as you're careful about removing the speaker so you don't damage the small plastic pegs on the top & left sides, you can skip Step 25 - 34 and save a lot of time.
The original part bends the bottom home button connector back on itself into a bracket you have to remove (not mentioned in later steps).
That bracket has a bit of adhesive to keep the bottom connector in place.
The replacement part does not come with a bracket, or additional adhesive, so the bottom connector flops around & can make reassembly a challenge. I found it was best to hold right edge of the bottom in place w/1 finger, and use a 2nd finger to slide the upper cable connector left to right and click it into place.