Well, I finished replacing my friend’s iPhone 3GS’s screen. He wasn’t too worried about some things going a bit awry in favor of saving money on Apple labor + parts prices. So we got just the screen/digitizer on iFixit + parts (adhesive strips, small suction cup for removing the screen) for a little over $70.
Like most of my Apple-related repairs, things got a hairy along the way. Since his screen was cracked, it was a pain in the ass to get suction over the fractures. I eventually applied a piece of clear shipping tape down the length of the phone to improve suction. It came off, but there was no way to know it was coming. The ribbons were pulled off of their connectors with great force and I was a bit worried I’d ripped something.
The next step would be to remove the LCD, which went smoothly. Then I had to remove the glass/digitizer from the plastic frame that housed the glass and (previously) the LCD. This was the biggest pain in the butt and is also where I think I also broke some things on the phone (ambient light sensors). The glass was held onto the frame with a very strong adhesive. I used a hair dryer to try and heat up the adhesive, but it barely helped. The fractures in the glass make it impossible to pull the glass off of the adhesive in one go. So I was left chipping at glass pieces with a flat headed screw driver. I forgot about the sensors and accidentally jammed the screwdriver into one or two.
I eventually got the glass replaced and put it back together (but wasn’t sure if I got one ribbon far enough into its slide-in connector). The only things that appear to be wrong with the phone is a lack of ambient brightness adjustment, a missing chunk of rubber gasket from the border of the plastic housing, and the tiniest bit of buzzing during a phone call. I think the buzzing is the result of the slide-in ribbon being damaged by the rough screen removal.
Overall, I would’ve rather had him spend the extra $40 on the part that included the plastic housing so I wouldn’t have damaged the ribbon or the sensor. I didn’t realize that removing the screen while it was cracked would be so much more difficult. Oh well—live and learn.