Eight hours to replace screen and repair power on/lock button
1 - 2 uren
Glass was cracked in one place on screen. Power on button was frozen and did not work.
I spent about four hours replacing the screen. The other four hours were spent repairing the membrane switch for the power-on/lock button through trial-and-error. The membrane had become separated from the circuit board. I used tiny droplets of 5-minute epoxy to re-affix the membrane to the circuit board. I then found it necessary to add a tiny dab (pinhead size) of epoxy to the inside surface of the button (inside the circle at the center) to enable the button to depress the hemispherical contacter in the membrane to make contact with the circuit board.
I wore neoprene gloves to protect the phone and used a headband magnifier (e.g. http://www.mcmaster.com/#11555t1/=sn9x0c) to enable me to see the small screws and details.
This was very tedious work and it is necessary to go slow to reduce the likelihood that one will damage the iPhone components. I recommend that one NOT undertake this repair unless he has prior experience assembling miniaturized electronics.