The speaker on my iPhone 4s started acting up. It would work intermittently and eventually went out. I searched the web for answers. I found this to be a fairly common problem. I was told in a forum to blow into the docking connector and lo and behold the speaker would come back on. It did work at first but eventually it quit working all together. The speaker was toast.
The repair went relatively smooth. I followed the step by step procedures on the iFixit site. Everything was very clear as to the steps to be taken. The battery seemed to be welded onto the phone. That glue holds extremely well. I was a little nervous when putting everything back together. Also worried that I was cleaning the parts per the instructions but when I put the back cover on and turned my phone back on everything worked. Success!
As I mentioned my battery was glued into the phone very well. It took me a lot of work to get it out. I was very concerned that I was going to damage something else while trying to do this. I did break the tips off both of the Plastic Opening Tools I purchased during this procedure. Also, I laid out a white sheet of paper and labeled where the screws belonged as I took things apart. The screws are TINY. Make sure you are extremely careful with them. If you drop one or it rolls off onto the floor, don't plan on finding it. Most importantly, take your time. Go through the step by step guide on a couple of dry runs before taking anything apart. Read everything and look at all the pictures. Again go slow and take your time.